My wife gave my a Onkyo 7.1 system as an anniversary present. (God I love her)
I am looking for advice on installing cooking fans to an existing cabinet as this sucker runs hot! and also unobtrusive ways to run the surround sound speaker wires. boring holes in the walls is out of the question according to the wife.
I would definitely use computer fans for your application. Two 120mm "silent" or low flow fans in an exhaust configuration should be adequate.
I would steer clear of wireless speakers. The sound quality is not all that great and you'll still need wires running for power.
Consider setting up your system in a 3.1 configuration. You'll get 90% of the experience and you won't have to run wires to sides or rears. And then you can say to the wife after she is wowed "Gee it would sound so much better if I could run wires through the wall and install the sides and rears..."