your better off converting to mpfi then convert to obd1 and using a p28...as it will give you a better fuel and ign mapping while in vtec. if ur short on cash stick with the dx ecu and just run an rpm activated switch like stated above.
how about if converting to obd1 that he uses a p08 ecu? this way he doesn't have to wire in a 4 wire o2 sensor. it should run nice as well. since this ecu comes from a d15 single cam vtec engine it might even run better. since that's pretty much what he will be building anyways. i could be wrong, i'm still new at this. just been reading allot.