Mesa Subway D-800+ OR Darkglass MT900 or Ampeg SVT-7 Pro?

Hello TBsers! I currently have a Gallien Krueger 700rb II and 2 Mesa Subway cabs (115 and 210).
Which one of the heads mentioned in the title would be the best complement (as in giving me different sounds that I would not get with the GK) to my current gear? Would the fact that I have mesa subway cabs make the mesa head the obvious choice, or it doesnt matter?
I play classic rock, hard rock and some metal.