The Gestapo didn't have any uniform. Since they were the "Geheime Staats Poilzei" (Secret State Police) they were not supposed to war a military outfit. Look at the guy from the first Indiana Jones movie and you get the idea of waht they looked like.
The idea of using Africa Korps troops for SA sounds reasonable, however, they were armed (if at all) with truncheons or maybe pistols. No heavy weapons, no rifles. German weapon laws were rather strict those days (still are). And no, they did not wear shorts. At least not after they were reorganized in the mid 20's.