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

I believe in this case of the original poster , he is looking for a plug and play to run the factory stuff on a stock engine with no interest to modify the engine or in tuning it. His best bet would be the stock ecm . Getting all the drivability as you would hopping into a new hemi car , which is why most people want EFI.

It is not uncommon to see newer cars with 200k or higher , running around trouble free with the factory efi. I have a Chrysler with 345k and have not had to replace any sensors on it. The newer stuff is very trouble free, and if you do have a problem , you will have stored failure codes to help diagnose .
You can look at a scan tool and it will tell you what cylinder is misfiring without lifting the hood.