Since your post was shown to be the end of August, perhaps you've already gotten your answer elsewhere. However, my wife and I just returned from a visit to SMA, and a stay at Casa Quetzal. The B&B is a wonderful place, centrally located, and staffed by a group of very helpful and friendly individuals. The owner, Cynthia Price, is also there. She is also warm and friendly, and eager to make your stay memorable.
As for restaurants, there are many excellent places. Our favorite was the Food Factory at Fabrica La Aurora. We also had a delightful meal at a Sri Lankan restaurant called Dila.
We also highly recommend the House and Garden Tour offered by the local library. It takes place every Sunday at noon. The cost is $15 USD, and worth every penny.