little gem suggestions south island please

two adults, two kids aged 8 and 9. up for anything, fit, well prepared, dont mind bush bashing or off track walks. we prefer camping to huts tho september we might be hutting it depending on temperature. the man is bringing the gun, snorkelling gear and fishing rods so we wont starve hopefully. looking at interesting varied places to walk which have fairly good hunting. we are leaving for south island monday spending nearly 4 months exploring/tramping using our caravan as a base, and yes we have ample warmth for our sissy "winterless north" bodies. We are from northland so not really experienced in the white stuff but all of us have tramped in it. On list weather permitting is mt fyffe, mt titiroa, mt somers, mt owen, inland pack track, rock and pillar range,lewis hut on heaphy, sugarloaf pass, nina valley, beally spur, moss pass in november maybe, charming creek, okarito and various day walks and rail trails. Are there any little treasures that you would like to share with us? beach, bush, rail trail or campground? the kids are nature buffs and fascinated with geology. the adults like anywhere remote with little people. any suggestions would be much appreciated.