i think they’re all pretty much the same.. take into consideration how far away the tuner is and how good their customer service might be.. seems like zfg has taken time to make their rounds in this forum.. maybe feel them out?
as far as a tune, i would get at least 5.. 87 daily/performance, 93 daily/performance, and e50 performance if there’s e85 available around you.. and make sure you get the e85 app and tester to make sure your mix is exact.