well here's my two cents...i'd go B18....now its up to you which one you get...it's pretty much just an issue of how much you want to spend...the B18's have more torque generally which is something that most honda's lack...H22's are cool too...although they requre a little more riggin' to make them fit...i would say your best bet is a B18....the common motors are:
B18B/B18B1 (DOHC non-V-TEC)
B18C1/B18C5 (DOHC V-TEC)
I was going to go B18B1 a while back, they're cheaper than the C1/C5 motors...so i guess it's up to your wallet...good luck and keep us posted.