Well my long range do it all is a 338 norma in a 10 lb scoped rifle with 270s it will do it all--but recoil is on the edge of me liking it...alot of guys are recoil sensitive (me included--im getting more and more sensitive by the year)but for a out west starter--I'd say 280 AI..in most US areas you can get ammo for it...you usually land and most major cities have a bass pro or cableas. They have it--so stop in.If your international your pretty much screwed anyway--I have been on my fair share of international trips and my stuff did not make it one time out of 14 international trips--and it was my firearm that did not make it...so moot point.
7mm mag is a great cartridge--one of my favorites. you pay for it with powder. the 280 AI does 90% of the 7mm mag with less powder and blast--and I have killed a boat load of stuff with a 7mm mag and 168 grain bullets.
One short story on the 280AI. We had loaded some of the 175 elite hunters at a bit over 2720 with 7828SSC in his rifle, my 7mm rem mag needed right at 11 grains more powder to get to 2900 fps... we shot steel with that little 280 AI and at 630 yards put a neat little group of about 3.5 inches at 630 yards...got it all dialed in and shot a red sheep at 80 yards with it!
the way hunting is! get prepared for the long shot and shoot them at point blank range. Good luck on your selection.