For a month anything should do, of course depending on how many hours you're planning to play daily. USB is probably the cheapest and easiest alternative but it will add to the total count of USB devices, using the same interrupts etc. which may cause hiccups in your gaming peripherals.
What kind of a wireless router are you going to use? If proximity is no issue, is there any chance you could connect it either to your LAN port or directly to a USB port?