My vote would be the 7x08, since you are going to mostly shoot paper the recoil would be lighter then your other 2 choices. You can fire a lighter bullet with the same sectional density, which can penitrate just as deep, without going to a heavier bullet in the 30 calibers to get the same sectional density, so again lighter recoil. Better choice of ligher bullets for varmit hunting that will perform better then the 30 calibers because of there higher sectional density then a same weight 30 caliber bullet. I will take it one step further, in the future you may get into handloading, a very nice hobby and cuts shell cost and lets you have more choices of bullets and loads then factory in any of your calibers. It will kill anything you are hunting in WA, and gives you better performance with lighter bullets then the 30 calibers. My personal choice would be a 270 win, some may say it is on the light side for Elk, but I have killed many Elk with mine, and black bears. As far as rifles, all that you mentioned are fine choices. You will get many "personal opinions" on that too!!!!!!!!! Go what fits you and fells comfortable when in the shooting position, but they all will have close to the same stock dimentions. Heck Kilamor Joe killed over a 1000 elephants with a 7mm and a 6.5mm using solid bullets and a brain shot.
Bob