Full port Stainless ball valves are the bees knees. I got some from
Bargain Fittings (a vendor here) at a good price and I'm glad I spent a few extra $ over brass.
Also I got tired of the locking mechanism on the lever, so I took a piece of shrink tube and shrunk it over the locking slider. This way if I ever want to use the lock I just cut off the shrink tube.