With the CH28 you have to be careful when selecting throttle bodies. It looks like the EZ EFI V1.0 and E-Street throttle bodies are pretty much the same design and would hopefully fit. I believe EZ EFI 2.0, MSD atomic, and Holley Terminator throttle bodies would all be to long to work with the CH28 carb spacing.

Holley avenger EFI might be another one to look at, it uses the GM style TBI, with the injectors above the throttle blades and is more compact. I don't believe EZ EFI v1.0 or Edelbrock's E-Street control timing, where the Holley avenger can, if that is important to you.

Another option would be get a megasquirt and two of the GM TBI units.