King, one thing you may be missing is that the ECU you pick doesn't matter nearly as much as the tuner you pick.
A great tuner can make some pretty mediocre ECU's look good, but a poor tuner won't be able to do anything with even a great ECU.
Pick your tuner first, then go with the ECU that he recommends and specialises in. If for some reason he likes an ECU that you don't, find out why, and if you're still not comfortable, find another tuner.
Many guys who call themselves "tuners" can talk the talk but they really can't walk the walk. You're heading into dangerous territory with standalones & tuners, so be forewarned......