What's ethernet-wifi adapter? I assume you mean pci-e or pci wireless adapter cards.
No, I doubt USB wifi adapters work better than internal cards, unless you have issues with the signal and the internal cards don't have removable antennas.
Those long usb things work fine, but they're not designed to carry power or power devices from the cable at the other end. You're supposed to use them with a keyboard or mouse, or to plug the cable in a hub that's powered separately.
Anyway, you could always get a 7.5v or higher (12v would be best) wallwart adapter and have two wires carry the dc voltage to your device over the 10 meters then use a tiny dc-dc regulator (or a car usb charger if you want something retail, because those work from at least 9v to 15v+) to get your 5v that would power the usb device.
Even with AWG24 wires (a pair you pull from ethernet cable for example) that have around 85 mOhm per meter resistance, at 10 meters you're gonna have a wire resistance of 85 x 20 = 1700 mOhm or 1.7 ohm
V = I x R ... so at 0.5A (500mA) you're gonna have V = 0.5 x 1.7 = 0.85v drop ... so with 7.5v in , you're still gonna have around 6.5v DC in, good enough for a dc-dc converter to produce 5v.