The collected works of ultra-coriolis

Hi all!

I have Sun Blade 1000 and want to make a maximum upgrade of this machine.

1) what is the differences between graphic cards - XVR-600, XVR-1000, XVR-2000?

2) is it right that Blade 1000 could use two UltraSPARC III Cu 1200 MHz simultaneously?

3) what type of memory and what is the maximum amount of RAM?