Schools might not be the answer.
Sounds like you are motivated. You might consider buying Rosetta Stone or Barron's Mastering Spanish 1 and 2. These are audio programs with an emphasis on teaching the spoken language. I just ordered Barron's 2 on Amazon--yes I understand the difficulties of getting delivery to the DR.
I also understand your desire for a group setting--I just spent a lot of money going to a university based course in New York State for an immersion program. It had a good reputation, but the reality was not so good and I got a refund and left.
The key to language learning, in my opinion, is the mastery of the rhythms and structure. This can only be done with intense drilling and repetition--which can be done efficiently with tapes and guided, structured lessons. That's what you will find in the above published resources.
The NY course turned out to be some very well-intentioned teachers dwelling on grammar lessons from a text book and some silly games that left us all mostly in silence. By taking charge of your own learning and having the ability to repeat at your own pace and to "study the books' once the grammar and structure reveals itself to you through the drills on the tapes, you will create the muscle memory that is the essence of language learning. It is just like grooving a golf shot or a baseball swing.
Perfect practice makes perfect. Only tapes can allow for enough perfect practice. Yes, DR Spanish has its own idiosyncracies, to say the least. But you can pick that up via local tv and the usual social situations.
Frankly, I am done with looking for schools and will teach myself. You might have better results that way as well.
Good luck.