The bus fare from Sosua to Samana is about RD$70. Tourism is in the doldroms right now so you can pretty much take your pick on where to stay. There is another thread going right now on places to stay in Sosua that you might look at. Tropix is a very friendly place and is one of the places mentioned in that other thread. It is clean, secure, quiet, and not overly expensive. But isn't on the beach.
If you can specify what you are looking for, I'd suggest posing the question in a new posting with that as its subject. Most of the recent posts have been asking for the best possible value for the money, with no necessity for being on the beach.
Wherever you stay, you'll need to take a taxi to the Caribe Tours bus terminal for the trip to Samana. It is located in old Sosua, which is some distance from the area where the tourist hotels and restaurants are. For cab trips in Sosua, including to Caribe Tours, the charge is RD$50 for the cab.