You can get a Hondata s100 with boost option for $445. Having fully mapped out fuel and timing definately sounds worth the extra $125 or so above the cost of an AFC. It just came out, which is why the AFC is still so popular. So yeah, you can spend $300 and it'll run "fine" or you can spend $445 and have it fully tuned. And you don't have a stupid-looking AFC cluttering up your interior.

As for the injectors, pretty much any 88-91 Honda will have the right resistor box. One box will run four injectors. You want the clips off of the DSM, which you can generally find being sold with the injectors.