I wanted to know the names of the clubs with the hottest women in Ibiza. Also what types of girls will I find there? for example, snobby, easy going, approachable? Do I need to speak Spanish or will the locals understand me?
That depends largely on what nights you go to. If you go to a night in San An, for instance Wonderland or Hed Kandi, most of the women will be British, drunk and / or high and very open to being approached, and generally quite friendly. Most of the girls that I saw at Hed Kandi ended up snogging someone on the dance floor at some point but whether that went further, I don't know.
If you go to a night with lots of Italians, expect lots of attitude and Italians don't generally speak very good English. The Spanish don't either, but it's not a problem for me as I speak pretty good Spanish as well. The Spanish are also much friendlier, though the problem of talking to people in clubs is that it's very noisy and it's hard enough to hear what someone's saying in your native language. Add to that the fact that a lot of people will be mangled, and that a lot of those won't even speak English as a first language, and you have a recipe for getting nowhere.
if you really want "hot girls" you could always go to a brother. There are a few legal ones on the island, there is one called Pure Platinum, all the taxi drivers will know it. The girls will be really hot. I don't know your reason for going to Ibiza, but if you are solely going there to get laid, it might prove a little more difficult away from San An / the nights frequented by lots of Brits. I've always gone for the music but on my recent trip my mate had the same attitude ("where can I go to find lots of fanny") and it got really annoying in the end. If you're good, you might to try some "day game" around Bora Bora / Jet Apartments and I've seen people do it, though again, it was with English girls. Good luck.