I know of one place where you can get the blades ,you have to make your own handle .
No they are not hard to sharpen
Try this site http://www.traditionalwoodworker.com/Carbide-Burrs-1_8-Shank-Made-in-Germany/departments/199/
You will surely find what you need
P,S You can try kutzall burrs they are quite agressive
Yes it is a good buy if you want more info on diamond tools go see diamond tech
And with diamond tools do not push too hard let the diamond do it's work ,and use plenty of water