Skip the damsel, they are always ending as terrors. I'd be pretty happy with the stocking of the 32 as it is.
When it comes to yellow watchman gobies, they pair with pretty much all common snapping shrimp to my knowledge. There are some out there that won't pair, but I would find it difficult to see them at most LFS
...and the ones that would get them in would most likely be able to tell you if they would or not.