First,it would be helpful to supply links so folks don't have to Google. For sizing,you really want to at least sit on one at the shop. It's hard to fit people over the Internet unless you know how bikes fit you. What size is your other bike? How well does it fit?

As for the various models;IMHO,I'd recommend going down to the Elite. The Pro and Comp have 'nicer' bits,but you're really not going to notice much of a difference unless you're in a competition. And quite frankly,I wouldn't compete on either as they're not real 29ers;unless things have changed since my old '06 Crosstrail,these don't have the clearance for 2"+ 29er knobbies. They're also both 10spd;10spd chains and drivetrains wear out quicker than 9spd(Elite's) and are more expensive to replace. The Elite has the same frame,a fork with lockout,and Shimano hydro discs,so for commuter/casual duty it'll do everything the other two will do,for much less.