I used a homemade ECU called Megasquirt, parts and technology obtained from these knowledgeable guys:
http://www.bgsoflex.com/megasquirt.html
to run a GM TBI on my 258 jeep motor. I used all junkyard parts except the fuel pump and Megasquirt ECU. Made my own adapter to the jeep intake using a 2 1/4 thick block of aluminum. Heavily bored out the stock plenum to make best transition to the GM tbi. Been running it for 3 months now and it kicks ass. Can idle so smooth and low the alternator won't charge, has instant throttle response at any rpm, starts at -30, and makes the best power I've ever seen from my 258.
More info available here:
http://members.shaw.ca/megasquirt/MS FAQ.htm
Cost to me was about $500.00 to put together. Used a tbi off an 89 caprice with 305 and used all the old sensors, except 02, which my jeep already had. Inline fuel pump (Carter F-M, don't recommend, it's too noisey).
Was easy to set up. The ecu tunes with a pc,or on the road with a laptop. You can drive and datalog to fine tune the VE table that controls fuel delivery. It's a simple, no frills speed density system that will work with TBI, multi-port and pretty much any engine with a distributor, batch fire, not sequential if you want multiport. Runs closed loop or open loop, speed density or N-alpha.
Advantages: Its an inexpensive, highly adaptable, tunable to any engine ECU that you built it yourself. Has great software support for tuning and diagnostics, and is proven reliable. If I want to swap to a larger than 305 V8, I can just change to larger injectors (or grab another $20.00 TBI) and retune.
I liked my Motorcraft 2100 carb, but you can't beat the power and throttle response this setup is delivering.