Assuming the number of dives in your profile is correct, I think you want to become a master scuba diver (MSD). In order to do this, you need to have at least 5 specialties, it doesn't matter which ones. Personally, I always recommend deep, navigation, wreck, night and nitrox, because I believe these are the ones that improve your experience most and open new doors for you. However, talk to your instructor to find a set that works best for you. In addition to the specialties, you need to have at least 50 dives, and you need to be a rescue diver.
An MSDT is a Master Scuba Diver Trainer. This means an instructor who can teach at least 5 specialties and has a certain level of experience teaching. If you want to become an MSDT, best to have a chat with a course director.
Edit: you mentioned self certify earlier. As an MSDT you can self certify to teach a specialty, provided you can proof sufficient experience in that specialty. Self certification is only possible after you become an MSDT, and does not count towards it. If you are a divemaster or higher already, you can find details on MSDT on page 182 of your instructor manual. Again, a course director can teach you how to teach specialties, so find one and have a chat with him / her