There are very few choices if you require a viewfinder. How small do you mean? How much is good optical zoom?
Starting with Canon, they offer the very cheap A1300, a 16 mp camera with a 5x zoom. Then it jumps to the SX50 HS, a 12 mp camera with a 50x zoom. The SX50 is a superzoom camera, so it is not "small." It will not fit in a pocket. After that is the G15, a higher quality 12 mp 5x zoom camera. It too is not so small, but at least it is flatter compared to the SX50.
Nikon the choices are even less. They only make the P510, which is similar to the Canon SX50. They also have the discontinued P7100, which is similar to the Canon G15.
looking to purchase a Canon or Nikon small digital camera....with view finder..12 MP or more and good optical zoom...any suggestions?