Wireless speakers, especially for surround sound purposes, are not yet ready for prime time.
And then there's Sonos, which works fine for whole house (stereo) audio, but is not good for surround sound needs.
Stick with an entry level 5.1 systems/speakers, and use audiophile sites/youtube to learn how to hide the wires. It's easier than you think.
I like the Sonos playbar but the sub is too expensive. Are there other "wireless" theatre systems that I should consider? I am looking for 5.1 so back speakers should be wireless too...