Chris I went a similar route to Jamie who also gave me some good advice,he knows his stuff
I can tell you converting to EFI made the biggest difference to how my car felt and drove to anything I have previously changed
I am now rebuilding the engine due to a track mishap but the good thing is EFI is almost future proof and will compliment my planned mods.
Do your homework,read up before spending any money and it will be fairly straight forward to fit.
The throtle response from EFI is insane ,its not all about outright BHP