I actually found quite a lot more alternatives, so my question is:
Do those converters make the same function as the adafruit cable? If so, what is the difference between ones and the others?
Thanks
You can get USB to TTL serial converters very cheaply on eBay, makes sure that there are Windows 8.1 drivers available for the converter you chose for future compatibility many don't have a Windows 8 driver. It would also be a good idea to get one with hardware handshaking, but these are rarer and cost more.