This is gonna sound complicated, but here goes:

If you want to get an idea as to how the different 7mm stack up against each other (or most other cartridges) go to remington's website. There's a free program call Remshoot you can download. (Go to "products" then "ammunition" then "ballistics"...you can use the thing online or download a slightly expanded version of it by clicking on the little graph icon) That program can give you a graph comparison of Muzzle velocities, bullet drop, wind drift, energy levels and so on.

Personally, I'd look at 30 calibers if elk was on the ticket. However, I'm also the guy who's looking pretty hard at the 25 cals for deer.