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

I know it's not the norm, but if you keep your eyes out you may be able to come up wtih a used system cheaper. I got a full Megasquirt system (MS2 if I remember right) with wiring and several other parts for a good deal under $1000. Sold off some of the parts I didn't need that came with it and probalby ended up getting it for $500 or less all told (granted I didn't need the spark control since I already had an MSD box, so in the long run I was closer to $1000 for all the computer systems together). I know the Megasquirt is expandable for future upgrades, but you might be able to catch someone selling an old one if they want to upgrade to a completely new unit.

I started with a carb and MSD and had the car running pretty cheap. Got a good deal on the MSD and harness with just some Google searching and reused the carb that was already on the engine in the car. Intake + MSD put me around $1000-1200 if I remember correctly (potentially cheaper with a different intake) to theoretically make the car run (I needed a few other odds and ends since my engine came with little to no electronics). Sold my stock intake and throttle body to help offset the cost as well.

The big thing that held me back from EFI originally was the fuel system upgrade required. I wanted an in-tank pump and didn't have the money or skill at the time, so I kept the carb so I could get the car on the road sooner. Got a job and some extra income and did the EFI upgrade when the computer fell into my lap (guy I sold the intake to set me up with the guy I got the Megasquirt from).

I really enjoy the Megasquirt so far because it is so adaptable. You can build it to do almost anything if you have some electronics knowledge and even more if you have some programming knowledge to set up your own stuff in the code. Granted there is a lot that you can change (not that you should or need to), but the basic tuning is easy enough for most people to pick up fairly easily for a reasonable tune. An example I have is that I started my setup with very basic O2 feedback control. As I got the base tune figured out I stepped up the O2 feedback to have a more accurate calculation that fixed the mixture more precisely. You could even turn it all the way off if you want. The same goes for idle control. I currently have mine set with a very basic temperature to IAC position chart, but you can make it do more complex stuff like idling at a target rpm and auto-modulate the IAC to do that (useful for when stuff like A/C or in my caes electric fans kick on). I've tried a few times and have had a few issues, so I just keep it off for now, but if I ever feel like messing with it again I can. You don't have to have everything set up from the get go to make it work, you can slowly filter in new features as you get comfortable with them.