@Budgie if you want to find out the differences, well, you could try purchasing one of each. I actually started with RTAs and I'm glad I did. The main differences for me include: it's much harder to wick an RTA without leaking, especially at the start. It's one reason that RBAs are often recommended to start, as it's much harder to get leaking at first (not impossible, but WAY harder). It can be a good way to figure out coil building and wicking, which can be trickier in an RTA, especially wicking and not leaking.
I started with RTAs because the idea of dripping didn't appeal, that and the wide bore usually needed to drip, I just hate that type of drip tip. With that said, since you are considering buying two atomizers, why not try an RBA and an RTA. If the RTA gives you grief, well you can wait on setting it up.
Also, if you like the idea of an RBA and not dripping, there is always the option of a squonker kit, where a juice bottle is inside the mod and you "squeeze" instead of drip. I'm not there yet, although I'm sure at some point I will try squonking. Seems like more and more great options emerging in that area of vaping. I'm not necessarily suggesting it for right this second, but maybe down the line.
Best of luck,
Anna