David-

Way to go!
I make my own overpowder cards and wads.
The cards I make from milk carton material, the wads I cut from saddle felt.
I cut my cartridge wads and cards with simple arch punches or modified hole saws (teeth ground off, edge sharpened, cutting surface square to cylinder of the hole saw)
These can also be easily be bought from track of the wolf.
You will also need to buy or make some wad lube.

On patching roundball for cartridge use, I don't do that myself. I shoot roundball of groove diameter or very slightly larger in diameter.
I make sure my card/wad column is tight for as good a gas seal I can get.

Once you get this rifle running properly with blackpowder you'll be hooked.

--Tinker