Basic question about PS pump gaskets...

[amolao]

I need a gasket (o-ring type) for my 1989 PS pump. I would like to know what kind/material o-ring is needed normally in a PS pump. Im afraid of using a regular rubber o-ring and having problems later due to the ATF damaging or eating thru the o-ring....Nissan sells the whole rebuild gasket kit, but I need is this one:

http://nico.zeroforum.com/zerothread?id=464481

any suggestions?

Thanks