I have a Tiny Terror head right now, and may someday get a Marshall 18 watt head (or clone), or a Matchless Lightning (or clone). Which speaker will go well with all of these type of heads? G12M Greenback, G12H30, or Celestion Blue? Would you go open or closed back? I play classic rock influenced originals, and some classic rock covers. This will be my ultimate grab and go, so I need a speaker that will sound good with any of the low watt heads I grab.