If you want to get FI you should just get a 3.0 block.
Look at the BIG picture:
Do you want PAS?
Is Targa really a must?
Do you want a lwt car NA with Headers and exhaust circa 300 BHP or do you want a heavy cruizer GT style?
Don't forget that at the very least you need £8k for FI closer to £ 10K to do it right.
Cheers,
AR