Need small size speakers for fireplace.

Hi, You should check out "Gallo" Due's, I'm using 3 of them for my front speakers in my home theater setup and like them very much! There is a pair for sale on e-bay that I saw yesterday for $600.00, Great little speaker!
Good luck with your search, Tish

Unfortunately, squeezing speakers into a small compartment like that is about the worst thing you can do to them.  The Tannoy Revolution XT Minis would fit in there, but I'm not sure what it would sound like.  Tannoy makes a pretty nice sounding and looking speaker, the tweeter is set into the middle of the woofer for superior imaging.  

You haven't mentioned what will be driving the speakers, which would help.

Yes, Geoffkait was spot on in recommending the Pioneer SP-BS22 speakers. Andrew Jones of TAD fame designed these and Stereophile raves about them. I bought them and was impressed by what they could do for $129/pair.

Geoffkait,  if your are referencing to the Pioneer SP22s, they are too large. I have owned a pair and agree that for the money they are exceptional.

I currently have a pair of Wharfdale Diamond 10.0 in place, also have a pair of Celestron F-10s which i have used. 

Runnin,  I must admit that I often think that I might do well with my current setup given the acoustical constraints. I mentioned speakers that cost upward of $1500 retail only with the intention of buying use. I realize that I am not likely to get the most from any speaker, however may be able to do better without great cost.