brabus

ANG fighter slots are extremely competitive, but yes, if you get hired you know what aircraft you’ll be flying. Though, you still have to make it through all the training and things could happen such as your unit switching aircraft when you’re 1/2 way through UPT (rare, but it happens). Fighter pilots fly a lot in the guard, even most of the part timers are flying a similar amount as the full timers. 
If you go the Navy route and don’t fly jets, your chances of flying fighters later in the guard are extremely small…don’t count on it. 
Go ANG over AD, and especially over the Navy. Do well in college, get your PPL, and consider enlisting in a guard unit you’d like to eventually fly for if that works out for your life desires (gets your college paid for at least partially and you make connections at that unit).