The people who go to the north Coast all say the North Coast is better. The people who go to the South Coast all say the South Coast is better.
If you go to the South Coast, though, you definitely don't have to worry about any long bus rides.
Santo Domingo is the Capital, and most populated city. As such, there's definitely the biggest variety there (not only in terms of girls, but restaurants, things to do, etc.). Take a look at the photos of some of the "great looking girls" posted on various webistes by the North Coast habitues, and judge for yourself.
However, I doubt this is the best time to go. yes, they need the $$, but my guess is that it's going to be fairly uncomfortable since NOTHING WORKS down there (hey, even without the recent disasters, the power went out twice a day). Recently, no power meant no gas for the water trucks, so a lot of people got sick since food was being wshed with the "local water" instead of "well water". Don't forget you're still talking about a pace where "middle class" means you have 3 walls and a concrete floor.