Hi, just saw this post, and if your questions were answered already, please disregard my post.
I have the full length SRS and while the Covert is very cool and impossibly short, unless you are planning to run and gun, PRS matches, etc with it, then my vote would be the full length version for a couple of reasons.
One, the bipod placement will be more stable the farther away it is from the centre of gravity of the rifle, and two, if you are planning to run those pricey optics on it, you are putting them at risk by having a short hand guard with short barrels on it and subjecting them to muzzle blast.
As far as optics, all above mentioned are fantastic, just depends on what you plan to do with yours? I am basically just a long range steel shooter and load development at the range guy, no comps, so super clear glass and high mag are what was on my list. I decided to go with the Zeiss 4.8-35 V8 scope, and it has the best glass I've ever looked thru. I also have S&Bs and a buddy shoots the TT, they are awesome too, but the price tag is crazy on those. If you are going to hunt, do comps and such though, the Zeiss is not the best as it has limited reticle choices and a smaller amount of internal elevation and weaker turrets then the TT and Schmidts. But the glass clarity and eye relief and eye box are unmatched in my opinion. Plus save 2K on it compared to the TT.(Can't go wrong with any of those optics).
As for mounts, be aware the SRS has no built in MOA rail, so you definitely may need an MOA mount to get you out to really long distances. I hear the SPUHR stuff is fantastic but never played with one. I have bought 2 of the ERA adjustable MOA mounts for my rifles, and they are fantastic. Super well built and 30 second MOA adjustments from 0 to 70 MOA of elevation with out changing anything on the scope, very very cool.
can't go wrong with either DTA though, they are highly addictive and so accurate. Cheers.