Budget EFI Kit

I am very Interested in this. I can't afford to go fast, so good reliability and fuel ecomomy are what I need. I like driving my car, but not at the price of gas right now @ 18 mpg with my TQ.

I have two questions,

does the fuel system require a return line back to the tank?

I have a stock cast iron singleplane 2 bbl manifold and a stock cast iron 4 bbl spread bore manifold. Which would give better performance with the TBI?