i have an i-mac that i just picked up and is connected to a cable modem for internet. i want to also hook up my old pc that was previously hooked up to the cable modem. what all do i need. btw the mac is in the basement and the pc upstairs on the 2nd floor. will a router (if thats what i need) work with both a pc and mac. thanks in advance. scott. also does the network speed suffer if i go wireless.