I don't recomend using an FMU, there just a "band aid" not fuel managment. And be advised that using the AFC will advance the timing. If your a baller EEprom is the way to go but right now, off the top of my head I can't tell ya much about OBDI (OBD0 for life!). There isn't really a simple, cheap, effective fuel managment for hondas, fun huh? If you have any more questions, shoot. This will help ya out to:
http://www.honda-tech.com/zerothread?id=377208