Get a job grinding castings
I worked at a large titanium foundry out of highschool, and I pilfered literally thousands of resharpened carbides. We used to just toss them because only the new ones will cut Ti.
Sorry I know that doesn't help, but I also would like to know if anyone has a preferred source for stones, flappers, burrs, etc...
-Edit-
Oh by the way, make sure you use some cutting lubricant when using aggressive burrs on Aluminum or it will clog the flutes and make them worthless in no time.