I just got a nice pair of rear speakers to complete my system and then figured out there is almost no way to run the wires (without wires dangling all over). Are there good quality wireless transmitters/receivers/amps that can hook up from the outputs of my amp to the speakers and get good quality sound and power?
No there is not. Sorry to disappoint you, but the main requirement of a good speaker to deliver good sound quality is power. If you can't get power to your speakers, they are useless. Most wireless speakers are very low on power and thus will not be a good application.
Have you looked into ribbon speaker wires? You could hide them along the edges of the wall better.