hi dominic,
Encuentro, located between Sosua and Cabarete, is the best surfing spot on the island. Also when there is swell, playa grande can be good as well (located about 45 minutes from Cabarete). There is also a good spot on the South Coast a few hours from Santo Domingo but I think lodging is spotty and not sure about the consistency.
For lodging right at Encuentro, I would do a search on Coconut Palms or Hideaway which are close to Encuentro. However, you might also want to check out Ali's Surf Camp
www.cabaretesurfcamp.com in Cabarete. It is located behind the main street of Cabarete in "pro Cab" and has many different lodging options from hostel type huts, to simple individual bungalows to nice apts with fully equipped kitchenettes. The atmosphere is casual and the restaurant is a local favorite.