Dr. Roy is a regular over at RC and has a Mantis ID page that you might find usefulUnfortunately Mantis are hard to come by around here and when one does come along it's never identified.
Don't let their size fool you, they are scrappy little things.The only psuedochromis I could find was a strawberry and he would have been fighting well out side his weight class as he was tiny in comparison to the damsel.
Not much luck on finding a pseudochromis. I did come across a larger strawberry but got distracted by a bicolor blenny which I bought for another tank. The strawberry was gone when I went back. The only other pseudochromis I can find is a vampire. Anybody have any experience with these. Some sites say they are less aggresive than other pseudochromis. It's also a little pricey and this particular store tends to be a bit overpriced, so I expect it's probably not a good deal.