need some help guys (parts wise)

Well i bought another 91 crx si. This time i am doing a zc swap (black top). The block is up at the machine shop getting alot of goodies done to it, but the thing is i want to replace the oil pump and having a very hard time finding one on the internet. Would it be best to use one off the d16a1 or the d16a6 block? are their any differences?

thx in advance,
-Wes

Zc Black top
Gude cams
Port and polished head
Milled the head 20thousands of an inch
Bored the block 40 over
slightly bigger pistons
Zc Ecu that has been jet tuned with the rev limiter shot up to 8500rpms
Dc sports 4-2-1 headers
Aem Underdrive pulley

Not sure on the suspension, i might try tien out with agx shocks