Well they should both work, there is a usb booster you can buy for the wii that increases the signal strength and distance of the signal for your wii (Highly recommended I have a wii) and to connect you have to go to the settings and select your network and put in all necessary passwords unless you have an open connection like I do lol.
Now for the ps3 I have no clue I am planning to get one after my 4th 360 craps out, its not long now. It happens quite a bit :P
Edit: Didn't notice if you said you already have wireless or not?
