Hey there Suthunman, first, welcome to CHR!!
As for the primer, many guys here use the epoxy primer from these guys
Southern Polyuerthanes, Inc.. You can order from them or they may have a jobber in Little Rock. Either way, give them a shout. You can usually speak to Barry the owner and he's very helpful plus makes great products! Like MP&C suggested, you and mix up a little and roll it on with a foam roller to get quality protection. It will get sanded smooth when prepping for paint.
As for the tail pan, I suppose you could 'glass it to the fenders but wonder if there might be a time that you would need to remove it for some kind of repair back there. If that's a possibility, it might be better to figure some method of hidden fasteners or something. Perhaps someone with more body experience will have some more specific ideas, Hope that helps a little!!