Go get the HD units from a NAPA, they have the grease fittings and hold up to a lot of abuse. I have a friend who owns a general repair shop and uses these in a lot of fleet vehicles.
any u-joint from any mustang vendor will work. They all come with grease fittings now. I bought one of those "heavy duty" ones from napa and the grease fittings suck. Its the needle type. I beleive they are all 1330. Nothing special about them. I actually took the napa one off and put 2 in from mustangs unlimited. I run aluminum driveshaft as well.