While I've not seen anything else other than EdGI's barrels, it seems like a good set IF (AND ONLY IF) the trigger sears can stand up to the pressure of an M160/M180 spring. I've not seen a good replacement for Laylax's Zero Trigger system yet.
Also, if you've never pulled back a huge sniper rifle spring before, be prepared. It takes a lot more force than a stock spring. A lot. Most people cannot pull a 550+ fps bolt back from prone position without bringing too much attention to themselves, and needless to say your rate of fire will drop 70% or more.
Edit: If you want it done right, take the time and build it piece by piece. Start with Laylax's PSS10 Zero Trigger (the one that includes the piston) and go from there. You'll have a better final result, and you'll feel better about yourself for doing it all.