Pretty sure Cincinnati is a Delta hub. The best connection from there would probably be through Atlanta on Delta. As far as cheapest, forget that. Anywhere in the Midwest is NOT going to be cheap. Depending on season, a GOOD price is probably going to be $700 round trip. (By the way, not that it really matters, but the airport for Cincinnati, I'm pretty sure is actually in Kentucky...) You should be able also to have a non stop to either Charlotte or Miami and non stop to SXM from there, on AA. If it's in the winter, better to connect through Miami, if you have a choice, versus having to connect in Charlotte. And NO, no way would I personally make TWO stops. It's just asking for trouble. The more stops you make, the multiplier of the possibilities for things to go wrong go up exponentially. Not worth it!