I would go with some kind of 338, your 270 properly loaded and maximized will handle any lighter animals just fine even for longer ranges, the 300 WSM gives you a little more but not enough to cover what you listing. I'm not a huge 338 win fan but most of my experience has been with elk and guys who think that a 338 gives them a license to shoot them where ever, shot placement is still important!
"Pain is weakness leaving your body"
Derek, no problem, Like I said I like my 270's also. Killed an elk at 1100 yards with my 270 wby that Sniper2 on here owns now. I just went with 338 winchester over the 300 wsm because of alaska and big bears since those are the two he listed. We all just need more info from Shane as to what weight rifle he wants and if he wants an over the counter one.
Predictions are difficult, especially when they involve the future
Thanks for all the imput...Now I am completely overwhelmed.
As a Marine I have spent my time carrying the 14 pounder and then again the 18 pounder. I am not a fan of "hunting" with a rifle that heavy. My Sendero is about 9 and that is almost more than I want. I understand why we go heavy, it just sucks...I of course would love to spend the $$$ on a 338 Edge or Lapua, but I am going to be lugging that thing around potentially through the mountains. That is more than I want to carry. I really am looking for a lightweight that I will put a brake or port the muzzle.
What if I just rechambered the 270 for a 30-06? Any 06 fans. I am really trying to get into this long range hunting. As a Marine we learn ballistics of a 308 and that is it. (again that is why I jumped on the 270). I want to buy/build an all around mountain rifle that will ACCURATELY and with enough energy to do it all. Am I asking too much? Maybe a Sendero type in a 338 may be the answer, if they make one.
Heck no you are not asking too much. And yes, I am a big time 30.06 fan. In fact, I'll be taking mine to KY on Saturday for KY opener.
With what you are wanting, I think the perfect rifle for you is a 338 Win Mag. Take a look at Savage. They have done all the right things and frankly, their factory rifles shoot extremely well. I borrowed an outfitters 338 WM in a Winchester and it was a breeze to shoot. No muzzle brake either.
If you are looking at a future build, I think it is safe to say that the Hart barrel has been a proven shooter for the 338 edge.
If you are going to rechamber the 270, the 30.06 is a great choice, but you might as well consider a 338-06 also.
I don't see why you don't work on the 270 if your thinking about an 06. At the elevations I shoot elk I would not even hesitate at 600yrds and at some spots I would take it to 800yrds. Why not save your time and money and shoot the heck out of that 270 and learn how to long range shoot with it, then you'll have a good idea what direction works for you. My buddy shoot a 270 win and with booger speer 130gr bullets he's taken elk out just past 500yrds with no need to shoot them twice, now take that and load a long range bullet and you can see that you can reach out there a ways. The way I look at it your in long range hunting already but just don't know it or have been talked out of it with the 270 win.
Almost forgot, remember to re chamber you have to stick with a 270 cal like say a 270 Gibbs or set the barrel back a bit and go 270 WSM, if you re barrel then really step up and rock a 338 RUM or EDGE.
"Pain is weakness leaving your body"
338WM with 225grn bullets or the 300WSM with 190 or heavier pills. A perfect trade off for the two of them in my opinion. You could also load the 338WM with a 250grn match bullet that would do wonders but the velocity will be between 2550 and 2675 depending on barrel length. This will definitely get you to 1000yrds, but with a bullet this heavy make sure you have a break. The 200 Accu-bond, 208 A-max, or 210 Berger would be my picks for the 300WSM. I currently use the 210's.
"Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it.  But small is the gate and narrow the road that leads to life, and only a few find it.
If you find your self in a fair fight, your tactics suck!- Marine 1st Sergeant Jim Ryfinger
Friends don't let friends develop canonitis!-chucknbach
arguing over the internet is like the special Olympics....even if you win, you are still...special!
About three years ago I found myseld in similar shoes, wanting a very heavy-hitting light weight-ish rifle that was capable to 1000 yards or further. I did a bunch of research and listened to LongTimeLongRanger alot, as well as many other respected members of this forum. I settled on a .338 RUM and I couldnt be happier. While I think that the .338 Win would work, the Rum is better by a fair margin. Admitidlly I havent shot many animals at long range (whitetale doe at 500 yards), The gun works for eveything. It is a suprisingly good shooter for what it is and is under 10lbs i think (as I have never weighed it). I am confident to 750 yards on game, but the gun can do more than I can.
It is a Remmy 700 XCR, bedded and modified stock. It wears a Harris Bi-Pod and a Mark 4 4.5-14 M1. It is braked and has a pachmyer decelerator pad, but I almost think it doesnt need the brake if I shot 225's instead of 210',225's and 300's. I've taken on pretty hard hike in hunts and found it about perfect.
If you dont want to go with the RUM then I would go with whatever you get a good deal on. Either will work.