My Turn for a Cam question - 318 Build

If your asking between the 252 or the 256, they both will give you good service. If your going to do a little more playing around than what you think, then I'd say the 256. If you truly believe that you'll hardly ever step into it, then the 252 would do just fine.
I also know that altitude (I have family in Colo), and it's a killer on low end torque. There have been some good suggestions as well from others on cam choices.

You'll make the right choice for you, because I from what I've read from a lot of your post, you are no rookie at this hobby :)
Sounds like a tough teener, I like it!