finding out that your motor is newer than you thought is a good thing. The bad thing is that hopefully it was properly converted to where it is now.
I would pick up some DSM 450's for $50 and put those in just to be sure I knew what size injectors are in there.
Next I would get rid of your distributor and get a new one. Keep the external coil, you may need it some day.
Next ditch the FMU and get Hondata or some kind of decent fuel management...
that should solve most of your drivability issues.

scott