Latin classes can be quite fun because the music is great. With latin dances there is much oportunity for eye contact because you partner tends to be further away. Even with salsa, when you aren't doing the real overtly sexy stuff your whole body's usually aren't touching.
With ballroom, your arm is all the way round their back and their stomach is pressed against yours and when you dance it is inevitable her breats will touch your chest at some point. Obviously if you are new to this and the girl is hot, there is the potentila for boner territory.
However ballroom feels really awkward when you first start and you can lose your balance and step on the girls feet etc.
Both Have they're advantages. If I were you I would try and find some good tango classes. There are 2 types. Argentine tango is a little like a latin dance. Ballroom tango is a ballroom dance but the hold is different and EVEN MORE intimate with your thighs aways being pushed up against each other etc and your back not so arched and your hand even further round her. If the girl is hot it feels really amazing to dance ballroom tango.