Gnomes (closer to the D&D variety than the RM variety).
I was thinking of giving them a quasi-oriental culture, and including a tiny bit of magi-tech/steampunk as well. They would have guns as well, but they would be highly inaccurate, and take a long time to load, and PC Gnomes would NOT start out owning any (though they would have knowledge of them).
I was also thinking of the possibility of doing a magical variant of firearms (also expensive) or even just magical items (wands and/or rods) that could simulate.
In any case, the inclusion of firearms would not unduly unbalance things as the time between shots and/or the accuracy would be problematic, and the damage per shot would also still be within current ranges (the most important aspect of firearms, I think, would be that it often ignores DR from armor....)
Thoughts? Comments?
(Note: I am exploring this possibility, not decided on it entirely)