Is there a true plug-n-play setup for a 5.7 with FI yet?

Not bad? I spent only a bit more on my Holley (HP) upgrade, and I can configure it to operate in many different ways. TBI, multiport, spark control, and many other special setups, turbo, etc.

I'm not sayin' that's "the best" but if you decide to change the engine, cam, etc, you can retune it yourself.