You might try GunsAmerica.com. I've seen them occassionally there. I also sometimes see them in "Gun List."
I thought I wanted to get one of each, but then I saw some folks shooting them at the range. Lots of misfires, probably due to operator error rather than design but I'm not sure. They only use the #11 cap, and today's replica powders seem to need a hotter ignition like the 209 shotgun primer. Even a musket cap could be an improvement, but the Scouts use a non-standard nipple, and only #11's will fit. If you get one, be sure to:
a. Clean all the oil out of the barrel before loading.
b. Fire a cap to clear the ignition channel.
c. Use real black powder.
These seemed like the errors the folks I was observing made.
The Scouts seemed to be a bit more to disassemble when the misfires occurred. I guess I am just spoiled by the simplicity of my Knight and my Encore.
They are neat looking firearms though.