Cable does not depend on distance, thats DSL. Cable depends on the number of users who are currently online. You "share" the speed with everyone else. If you are the only one downloading anything, you will get great speeds, however if there are 50 thousand people downloading stuff, your speed will drop. DSL has a constant speed, but the speed depends on your distance from the company.
As got the networking stuff, unless it is USB 2.0 (which I've yet to see a router that uses that), it will possiblly be slower, if you have other networked computers. An Ethernet connection is 100mb/s, USB 1.1 (I forget the exact) but I think it is somewhere around 12mb/s. So if you intend for example, to play CounterStrike over your network, Ethernet is certainly the way to go.
Really, everything you've asked depends almost completely on your situation. Try investigating which companies are available in your area, how much they cost, and what services they provide. Thats probably the best way to go.
