the PSD kits used to use a facet fuel pump normally used for fuel supply with carbs. That's what I used too. The pump isn't ideal because they're designed for flowing fuel which is much thinner. I used compressor oil in mine and had no trouble, I ran a pressure gauge on the charger oil outlet so I could keep an eye on it.
Proper electric oil pumps are available but they tend to be £150+. That 200sx diff oil pump sounds ideal though if you can get hold of one of them. I would have thought a diesel pump runs waaaaaaaay too high pressure. You want something like 20psi really.