stay obd1 its a lot more bolt-on friendly
no need to change distributor or alternator just change the plugs on them to obd1 if u have an old obd1 dist. and alt. this works great it did for me. try to find a bad dist. and alt. from someone you'll save some money!
also the fuel injector plugs, if u have an obd2 harness still on the 99 motor just cut the plugs the off injectors (leave some slack) and wire them in to the obd1 harness
go with the p28 and get it chipped for the IAB scondaries and new rev limiter, p72's are high! or if u have some xtra money get a skunk2 manifold and don't worry about the secondaries
r u using the p30 on the b16 cause its pretty much the same as the p28 but better u can do the same to the p30 as to the p28