I recommend the Ixchel Spanish School in Antigua, Guatemala. I did one-to-one classes there for a month for 6 hours/day about two years ago. They were phenominal – the setting of the school is very comfortable and the instructors were excellent.

http://www.ixchelschool.com/

While they can recommend salsa classes and help with travel arrangements, that’s just an extra service for those students who want to get involved and meet more people.

The school can also recommend a hotel if you don’t want to do a homestay. However, I found that doing a homestay was a great – i stayed in a beautiful home only a five minute walk from the school. there were other people (mostly late 20s/early 30s professionals in grad school or on holiday) staying in the house, but you could choose to interact with them as little or much as you’d like. I actually made some good friends that i’m still in touch with today.

One note, though… 40 hours/week is a lot of time to do one-to-one classes. My brain was exhausted after doing 30/week, especially when you have to go home and study afterwards. Getting out and unwinding with whatever you happen to enjoy helps a lot – plus you get to practice your spanish a lot more in practical contexts.