Brookstone.com has a great pad....it is the same one they issue to the instructors if they want....I bought one and it was worth every penny. They are a bit expensive though....to the tune of ~$85.
The shiznit of ass pads are the big brown ones (like 3-4 inches thick), but they cost around $140 dollars and I'm not sure where you get them. Maybe someone else will post about them.
The paraloft does have ass pads you can check out with the rest of your flight gear but they are a F*&kin joke......about 20 years old and about .02 inches thick.
I know the ass pads can get pricey but I highly recommend getting something.....as the pain finally went away (ie first flight with the brookstone) my concentration improved dramatically and as a result my BAW and landings got better.....just my .02