You might want to check this thing out. i have heard extremely great things about it. I would still get rid of the Zalman heat sink. You are still 15-20 C above where I sit with my Prescott.
As for more mods... Just drop an Air Conditioner duct in front of your PC! ;) That or a top blow hole or a fan removing the hot air from the top of your case would be the next bet.
