Help with Boots, Sleeping Bags and Packs please!

Hey there, I'm looking at getting into tramping properly after enjoying a recent tramp/rogaine I went on, and would greatly appreciate it if you could answer my questions! Firstly, I'm after a good pair of boots. I've decided that lightweight boots would be best, as since I'll be new to tramping I wouldn't be going on any difficult hikes for a while and light boots will also suit orienteering/rogaines/day-trips which I'll likely do quite a bit of as well (possibly more than tramping). However, I'd like the boots to be able to hold up well for more difficult tramps in case I do end up doing them in the future (durability is a big issue since I'm a reasonably poor uni student so I'd want the boots to last me good 3-4 years ideally). I estimate that I'd use them in a tramping type situation once every month or so on average and would only do basic trips for at least the first year or so (trips lasting a few days at most). I have narrowed my choices down to either the Salomon Fastpacker 3D GTX or Salomon Cosmic 4D GTX. The style of boot seems to be the most suited for me and Salomon's last fits me well, based on a try-on of the Fastpackers (I plan on trying the Cosmics in the next few days). The Fastpackers were comfortable on, but I'm not sure about the sizes as US 9s are comfortable (though I am aware of the sides of the boot and am a bit restricted in the toebox vertically) whilst the 9.5s still feel comfortable but with more room inside the boot (I'm not aware of the sides/toebox when I have them on, which makes me wonder if they're too big). After tightening the laces for both sizes there was no little to no heel movement when I walked (only a small amount with the 9.5s) and I could fit an index finger down the back of the 9s (the boots were tried on with two pairs of socks, one merino and one medium thickness wool). While the 9s feel more comfortable, I'm wondering if I should go for the 9.5s to account for the whole feet-swelling phenomena and for if I get thicker woolen socks later on....Is there any fitting advice for such a situation? I know that I should pick the style of boot based on what fits better but my current concern is with finding what size fits best, which may be more of an issue than picking what style to buy! (If only shoes came in size 9.25...) Anyway, my main concern with the Fastpackers is that they may not hold up too well for more rigorious trips (in case I do end up going on them). For that reason I'm considering the Cosmics as they have a stiffer sole and have higher ankle support. However, they are 300g or so heavier than the Fastpackers which makes them less desirable for shorter excursions and while they've had great reviews on the internet, some people have questioned their durability which is worrying for me. Unfortunately the Quests (a more durable/heavy cousin of the Cosmic) and Wings Sky are not available where I am. I'm aware that the people who have said online that their Cosmics lasted only a few months likely used them a lot more than I plan to, but since durability is a big factor for me I thought I should ask here what the recommended boot for my situation is...Basically I would like a versitile boot that will suit short trips (orienteering, day-walks) and easy-medium difficulty tramps, and give me good value for money in terms of how long they last. At this stage it looks like I'll almost definitely get one of the Salomon pairs, which are going to be on sale a week from now, so if there are any recommendations on what would be best for my situation (assuming both types of boot fit me well) that would be great. I'm still open to suggestions for other suitable, similarly priced boots, on the off-chance they are available where I am (Christchurch). During the aforemented sale I plan on stocking up on quite a bit of tramping gear since a lot of equipment I need (packs, sleeping bag, sleeping mat) have 50-60% off. I currently have a basic synthetic sleeping bag which is a few years old, but since there's 60% off sleeping bags am considering upgrading now while they're cheap (my current one is very large when stuffed into its sack so one that can compress smaller would be much better for tramping). At the moment I'm looking at two sleeping bags; a top-of-the-line rectangular synthetic bag (with temperature ratings of -28, -10 and -3 degrees celcius) and top-of-the-line mummy style goose down bag that costs 3x the price of the synthetic one but has windproof/waterproof/durable/lightweight fabric (with temperature ratings of -30, -11 and -5 degrees celcius). I've heard that sleeping bags with down last longer and compress more than synthetic bags so would be willing to spend the extra if it's going to last me for significantly longer and be far superior in general than the synthetic bag, however the synthetic bag still has a very similar heat rating so if that's going to do the job and last a while also I'd rather get the cheaper one....If there's any recommendations that'd be excellent. Finally, I'm looking at getting a pack in this sale. The other night I bought a second hand, 6 year old (but good condition) 90 litre tramping/travel pack of a quality brand for a very good price ($96) and will pick it up soon. However, today I saw the catalog for the upcoming winter sale of the outdoors store already mentioned and saw that they have 50% off the travel/tramping packs I'd been looking at before I bought the second hand one. This meant the new packs would be $300 (from 600) and club members of the store can get an extra 15% off the total bill when $300 or over is spent (meaning the pack would effectively cost $255). The largest size of this pack is 75L, but it comes with an attached day pack which I estimate would be another 15 - 20L. Though it's not waterproof, I would assume it'd be fine for tramping, and it's attractive for its travel option too since the harness/straps can be zipped away (this is the same for the second-hand pack I bought). Once I pick up the second-hand pack, I'll try it on and see how well it fits. If it doesn't fit too well, do you think I should re-sell the second hand pack (I should be able to at least get back what I paid for it) and buy the new one for $255? Or should keep it anyway since I'm only starting out? For easy-medium difficulty tramps lasting less than a week, is 90L an excessive size for a pack? Would the new pack be a more reasonable size for such ventures? I'm also after a smaller pack for day-trips and possibly one-night trips, since they're also on sale. My options are a basic 30L for $60, a 50L hiking pack (with hydration bladder compatibility and things) for $119 or a 65L travel pack (with a 15L attachable pack) for $170. For day-trips I'm thinking the larger the pack the better (within reason) to fit bulky jackets and things if needed, but 65L is getting into quite large territory so if anyone could indicate what a suitable size for a day-pack is that'd be great. Thanks very much for reading this, any help at all would be much appreciated! Sorry for the long speel but I want to make sure I make the right purchase decisions since everything's so expensive (to me at least) and I thought I should outline my situation as clearly as possibly so you can have an idea of what angle I'm coming from.