I believe that IAR is an importer of the IAB model Sharps.
http://www.iabarms.com
I have one and shoot it a lot. It is more on the "bottom end" of sharps reproductions and there are quite a few design flaws with it, but for reenacting or occasional live fire shooting it should do what you want to do with it.
This model sharps, more than any other reproduction, needs to be maticiliously cleaned after each use. You will probably need to modify the breech plate as well to ease cleaning. Without that breach plate being able to freely move inside its socket, you will get a lot of gasses out of the breach and unnecessary wear to the breach block, plate, and barrel.