By all means, use what works best. I mentioned using 2F because my results always favored it from .50 calibre on up to an 11 bore fowler with round balls.

10 shots is good - those cases owe you nothing. With some loaders, paper cases (Federal still makes them) work well. You could even try Buffalo Arms brass cases, however they are only 2 1/2". That is what I used for my Husky.

Graff's and others in the States will mail BP right to your door in the States. You have to pay the hazmat fee, so getting some friends together if you don't want a case of powder will help lower the cost. The Hazmat fee is the same for your whole shipment, whether for a single can, a case of 25, or two cases at 50lbs.