If I had that much to spend, it would be on the Adam A-700 twin-jet - which is flying right now. Not as fast (only 340 kt), but has the benefit of 2 engines.
http://www.adamaircraft.com/home.asp
And for about half, you could get the A-500 (slumming it with piston engines, I know).
Now where's my lottery ticket...
SD