I actually like the cork gasket on the older style 20R/22R pans. They are usually flat though unlike the later model 22RE ones. I used the cork with that spray on copper looking stuff and so far no leaks.
On the later style with the dips in the flange I have used both grey and black permatex with success and the Toyota stuff a few times too.
I have found that whatever I use, I have a better seal if I wipe the mating surfaces down with acetone before application.
I think probably any of the popular Permatex gasket making products will work fine on the oil pan, with or without the cork gasket. If the cork gasket is allowed to "set up" some before torquing the bolts, I think it will seal fine.
I bought 3 gallons of paint thinner for my basic degreasing, and 1 galllon of acetone for final cleaning. I have used starting fluid as well for super cleaning. For the carbon inside the intake manifold and throttle body, I used a little steel brush and carb and brake cleaner.