Cabarete is very consistent and great for beginners although the water is not as flat in the "winter". Check out
http://www.kitexcite.com. They also offer lodging option right on kite beach which includes breakfast and storage area for your equipment. Brunotti boards can also be rented (getting 20 new boards in on the 15th) and Wipika, Naish, WindTools, North, Cabrihna kites as well. For general info about the DR, check out
http://www.drpure.com; http://www.activecabarete.com; http://www.cabaretekiteboarding.com and
http://www.cabareteairforce.com. Also
http://www.hispanolia.com has some good general info. Airfare may be a bit pricey but once you get there, it's very inexpensive. Nightlife can also be fun as Cab caters to windsurfers and kitesurfers. Good luck whatever you decide! Just make sure that the place you pick has a long, wide sandy beach and no reefs! Friends just got back from a place in the Caribbean and their kites got thrashed on the first day from sweeping their kites too close to the water (like a couple of inches!).