I'd expect either option to easily cover an entire storey of a typical house, never mind a single bedroom. The available wireless bandwidth will ultimately be limited by the speed of the Homeplug link, and that’s an unknown until you try it.
Normal Homeplugs plus the Edimax won’t be as neat as the combined option, but It’ll probably be cheaper and you gain some additional wired LAN ports you might find a use for.
Toss a coin, or let your wallet make the decision.