I'm definitely no expert, as I am in the same position as you- I'm acquiring parts for a build right now. As far as an action though, if you are wanting the best stuff - I'd look into a custom action (if you don't already have rem 700 for the project). I'm starting new (don't have a LA Rem laying around) and have heard from many on this site to look into custom actions. Your cost isn't too far off once you figure truing costs and adding other bells and whistles to the action. Just depends on how much a guy wants to spend!
I've found a Stiller Predator LA w/ 20 MOA rail for $900. It's a little more money than I want to spend, but in speaking with the gunsmith I've decided on, (Lane Precision Rifles) he'd prefer a Stiller over a 700 any day. There are some great shooting rifles built off of 700's, but just thought I'd throw it out there.
So far for me, I'm going with a 6.5 Sherman built with:
- Stiller Predator LA
- Manners T2A in Elite GAP
- Bartlein barrel
- Timney trigger