Wireless is a technical issue on its own.
While in regular computing size does not matter the 1 and the 0 are the same at any size.
In Video, Audio, and Wireless size does matter.
I.e., components that generate power and depends on peripherals (like Speaker, and Antenna) for their Job do not follow the rule off 1 and 0 and size does not matter.
USB Wireless is usually entail puny RF Amp, that has a little wire for Antenna, it has No heat dissipation so it throttle its power down after a while. s a result USB is not a good solution when it comes to Signal strength issues in Wireless.
Mini Wireless card thingies has external Antenna so that might not be a problem but their power output tend to be limited, thus they are Not a great solution unless they are already embedded in a laptop.
If you have a regular PCI slot, then use PCI it is the most reasonable solution.
Otherwise, something like the D-link linked to above is the next choice.
