Accuphase E-450 or Accuphase E-550

My speakers are Focal Electra 936 and I am using them with Accuphase E-213 in a room 19*22*9. and I feel I need more power than the 213 has.
I like to listen mostly to Rock and Folk.
Which amp. will be the better route: the E-450 or the E-550?
Will I get a substantial improvement over the 213 in bort amps?
I can not audition those amps.
Since I like the Accuphase 213, I think the best thing is to stick with Accuphase.
Do both amps will have enough power for the Focal Utopia Series(hope to upgrade in the futue) .
Your opinion please.