Finally got the balls and also found the wads online from Cabelas. Prices seemed pretty reasonable at $15 for the balls and $10 for the wads.
Not having a flask, I plan to use the appropriate size dipper to load the chambers. From this chart -
http://www.curtrich.com/BPConversionSheet.htm - it appears that I need to use a 1.67 cc dipper for a load of Pyrodex P equivalent to 25 grains of black powder.
Does that sound correct?
Another question - now that I have the wads, is there any reason to keep the Bore Butter or can I return that to Bass Pro?
One more question - I plan to load and shoot a single chamber, then load and shoot all 6. Presumably I can force the balls almost into the chamber with my fingers and then finish seating them with the gun's loading lever. I understand that I don't add the caps until the cylinder is back on the gun, the chambers are loaded and I'm almost ready to fire. Any problems with that logic?