Jim,
Took a look at the site. Intereesting to say the least. I can never fathom why you'd want to run at such a high rate of spindle speed. Usally the asnswer to that one is drilling small holes. I'll have to disagree with that since I've drilled .080" holes at slower rates without breaking them. Also I think a small mill such as the X2 isn't rigid enough to with stand that kind one speed. Plus, how long will the spindle bearings hold up.
Personally I'd never mod it for higher speeds. Just my 2 cents.
Bernd