For the coins I would possible try Stacks/Bowers as they bought out Ponterio a couple years ago which was one of the top US houses for world coins. On the other hand Heritage has been making real inroads into the world coin market. I believe they just did the auction at the Chicago International show this past weekend. (Ponterio used to do the auction at that show until Stacks/Bowers bought them.)
Lyn Knight is usually to top paper money auction house.