Thanks for all the replies,
There is a lots to choose from, now to look at the ballistics, reviews, and brass availability. I have been considering a falling block in 45-70gov till I saw a custom double falling block and fell in love. In single shot form 45-70 would be my choice. Now I have been trying rationalize getting one made. Being that it is a double gun I want it to be the most elegant but useful of cartridge as possible. As I plan on using it a great deal.
Again thanks for all the ideas.
Dan