The TH2G sounds nice, no more worries with cards and configs etc.
However, as far as i understood your (really great) howto correctly i think i would need 2 TH2G because my resolution is:
3600x1600 (3 x 1600x1200 rotated)
I don't even know if my Video-Card can output 1600x3600 (NVidia 7600GS), if the rotation works, etc., there are just too many unknowns.
2 TH2G would be 500€ and i think i would rather invest that into the new 27" Dell Screen with 2560x1440 that is about 900€.
Or use Windows where everything is easy and fast i assume