It's pretty easy to hammer the studs in yourself. Personally, I'd complete the finish and then install the studs. After having done 3 unfinished to finished bodies, this is my preference.
If you put the studs in before you complete the finish, you'll have to tape over and protect the studs as your putting finish on the body. If you do the finish first, and then gently hammer in the studs, you won't have to worry about the studs getting finish material on it, and you'll reduce the likelihood of a non perfect finish around the studs.