While I don't shoot competition anymore, I would recommend a Kel Tec Sub 2000 for glock mags. They aren't for everybody but they are reasonably priced and can shoot fast. I am used to carrying Kahr firearms so the trigger on the Sub2k doesn't phase me. If you shoot a Glock, you probably woudn't like it.
Only time I shot the Keltec was in the American Marksman regional competition. Needless to say I could have shot a lot better with my personal build AR-9. Did not like the Keltec trigger. While I may use mine in at least 1 IDPA match this year I mainly use in in Steel Challenge where I currently have a Master ranking in PCCO. I built mine based on what I wanted to do with it, not what someone else might do for a generic build.
Most either build their own, or buy a good off-shelf PCC like the JP. The new delayed blowback designs are intriguing, like the CMMG MKG, softer recoil and a lighter reciprocating mass(and lighter overall) would definitely be nice in a competition PCC. I'm, in the "build your own" camp, only way to get exactly what you want.