As for the rifle, it is indeed lightweight, but its accuracy, from what I have been told, is not as great as the Accumark. Nonetheless, the price that you were quoted, with brake, is a good one.
As for the scope, Kahles are good scopes, and a $100 rebate is great. HOWEVER, as you will be hunting elk/mule deer, and as the weather can change in a matter of hours, I STRONGLY recommend that you get the Bushnell Elite 4200. Trust me, although the Kahles is a good scope, the Elite 4200 is MUCH BETTER and has RAINGUARD which literally could make the difference in the hunt. I would recommend the Elite 4200 2.5x-10x-40mm. Go to dnrsports.com or theopticzone.com (two of our sponsors). You will see that they have some of the absolute lowest prices.
As for the cartridge, as you will be hunting elk and mule deer, I would recommend the 300 WBY over the 270 WBY. Granted, the 270 WBY would work on elk, but the 300 WBY is a much better choice. I would use stout 180 grain bullets such as the Partion, Barnes X, which is loaded by Weatherby, or the Trophy Bonded, which is loaded by Federal.
Zachary