On the face of it there is not much to draw tourists into Bulatsinhala, I've been there dozens of times and not once seen another white face, for me that is the main attraction, it's just regular small town Sri Lanka with friendly locals and no touts.
Market day is Sunday and the town gets busy but during the week it can be an almost sleepy place, excellent for tout free shopping. Local shops and small cafes have most things you'll want, there is also a pharmacy, clinic, post office and bank (no ATM). The bustling city of Horana, less than an hour away by local bus, has everything else you might need.
Near Bulatsinhala is the impressive rock temple and Buddhist seminary at Pahiyangala. Famous in Sri Lanka, Pahiyangala draws Buddhists by the bus load on Poya Day but is over looked by the guide books so you will have it largely to yourself the rest of the time. There is no fixed entry charge but your donation will be appreciated
Pick up the Horana bus at Panadura which is easily reached by bus and train from Colombo or take the bus via Matugama if you're coming from Bentota or Beruwala. At Horana or Matugama you can get direct and frequent buses to Bulatsinhala.
Is this your business?