First off...spend the money you would spend building you head on building your bottom end. Second
the B20 and VTEC B-series have the same oil pump, the B18a/b is wussier, but you can shim it to puto ut more pressure.
the waterpumps are totally different, I wasn't sure when I bought them if it'd be worth it, but the gear on the vtec one is a good 5mm wider than the non vtec one.