I have done a few of these. if you get a bunch of brake clean you may be able to save the ABS unit. you have to flush the whole brake system out and use tons of brake clean through the abs unit. if your lucky you can prevent damage. if its been in it for more then a day or two you smoked it.
as for things to replace,
1. Master cylinder
2. Calipers & wheel cylinders
3. rubber flex hoses
4. proportioning valve
5. abs unit if equipted
6. flush steel lines with loads of brake cleaner
by the way the most common reason to put P/S fluid in one is to have Hydro boost brakes. for some reason people think the whole systen runs on P/S fluid.