[MGunner]

I really want to look into an EdGI 5.98 or 6.00 super tightbore, but it vastly limits your ammo variety.

For now, I use the stock barrel in my BAR10 pro, a KM HEAD 430 barrel that I got for wicked sheap and cut to fit my G-spec, and I'm going to invest in a nice IB for my Tanaka ( ;D )

 

[MGunner]

what about barrel length? Which do you think is the best for power/accuracy with a vsr cylinder?

There was a thread on Airsoft Retreat many moons ago by a guy by the name of Noobie (same dude who invented the M-trig, TDC system, etc.) that showed mathematically how to volume match your barrel to your cylinder for a VSR.