Unless you have a wired gigabit router cat 5 would be fine, although if you are wiring a network for the first time I would use the best I could afford. The way technology goes it won't be long before you will appreciate that you put in the best cable. It's no fun to do it twice.
I am experimenting with my PSR500 and an audio bluetooth module that I plan to embed in the radio, to stream it to bluetooth ear phones etc.
fun Stuff