In brushed motors dual Trinity Monster MAXX Pro motors(17turns) will have a good deal more torqye than the 540 type you to have(looks that way from the pic).
I have a Novak HV-Maxx motor/ESC combo that replaced two mod 550 motors with ease.
Next up castle Creations will be releasing their Mamba MAXX setup(motor/ESC)that should surpass the HV-Maxx around summer time.
After you are looking at Hacker or Lehner with a Schultze ESC,these can be configured from very wild to insane.Power is measured in 1000's of watts at this level.For these combos you need a fully upgraded drive train or the power of these motors will chew up the stock E-maxx parts like nothing you ever saw.
For cells,I use the tried,tested and proven GP3300 sub C cells.Two seven cell packs and the E-maxx flies. 16.8V coupled with massive amps ready to juice up the brushless. Also all Deans Ultraplugs must be used,no tamiys style connectors.