Need small size speakers for fireplace.

Thanks everyone!  I have decided that I will reduce my budget to those speakers that can be had used for < $400. Given the placement constraint and supporting system that budget seems reasonable.

My list now includes:
Audioenjine P4
Dali Zensor 1
Monitor Audio bronze 1
Silverline Minuet 
Paradigm Atom

Hope to expand this list. 

Silverline Minuet will kill and eat for lunch any other speaker on your list .

Used for $400 is your limit thats fine. Just remember you'll get what you pay for. Better option, do without for a liitle while, double that 400 to 800. Your used increase performane will triple. Good luck

Dali Zensor 1 is a very smart choice; I am a happy owner of a pair of Dali Zensor 1 for more than three years and I'm very pleased with the overall result. No wonder they got so many good reviews and "Best Speaker" mentions under that category.
I suggested the Zensor Pico and the Menuet because they're smaller (though the Menuet is more expensive). But if you have room for the Zensor 1, give it a try!

Joejoe, as 213runnin mentioned, given my placement constraint, I will likely be diminishing the sonic value of any speaker I choose. This I new going in. Further consideration of this has driven my decision to reduce my budget to those speakers that retail at ~$800 or less as apposed to ~$1500. That said, what speakers can you recommend that fit my space constraint and can be found used for $800?

Schubert, I am confident I would also find the Minuets to be the best of my list, however retail at ~2x the price of the Zensors, which, based on reviews seem to be of high sonic value.  After further consideration I have shortened my current  list to the Minuet and the Zensor 1.  Thanks miqueca for the comments on the Zensors.

I remain searching for other options.