PS1000's are physically heavy and may not be the most comfortable. Depending upon your head shape, the top of the headband can hurt you over long listening sessions. If you want bass the PS1000s certainly have it.
The HD800s are light weight and comfortable for most people. They can lack bass and sound thin and bright - at least on most setups I've heard them on. If you are willing to mod this headphone, you can tame the treble down quite a bit, which does bring the bass out a bit more. The HD800s are hard to drive. It's more difficult to get bass impact and dynamics out of them; they are laid back by nature. The PS1000s are easy to drive. You can get good impact and dynamics out of them from modest setups.
I've owned the PS1000 and the HD800s are my primary headphones. I still like both for their good qualities.
As a few people have said above, your answer is "neither" for your requirements.
Edited by purrin - 9/1/11 at 10:15am