S&W no longer manufactures the Model 66 and I do not believe they ever made them in seven round versions. The Model 19 is the same gun except it has a blued finish instead of stainless steel. The Model 19/66 guns are very popular and there were a number of them made, so they are readily available used.
The guns did have an issue with the forcing cone being damaged after using lots of high powered loads. I think this issue probably gets overstated somewhat and with standard .357Mag or .38 you should be fine.
Can't say for certain, but pretty sure that is not a Model 66 in your photo.