Wireless surround speakers....

I know these are not probably ideal but first let me qualify my post...
I have an elderly couple who I have become very good friends with and I wanted to give them the gift of HT, nothing fancy, just A theater in a box deal, but I fear the wires going to the back speakers may be a turn off to his wife and maybe even him, so I want to know about cheap and effective wireless speakers for the surrounds, any ideas? thanks as always Chad