I ordered all porsche parts right here at Pelican Parts (maybe if I keep plugging for them I will get a dicsount).
I went to pep-boys and got a generic pump at first, but by the time I finished retrofitting it to mount it, I just figured forget it, I'll pay the extra $13 for the real Porsche pump (VW/Audi) and snap it right in.
My case might be special, if your pump is all that's busted when you replace it it should work fine again. I clearly have more issues to deal with. Hopefully one of the resident geniuses will chime in????
p.s. Prof- I want your life. Why must you taunt me?