Just to let everyone know, If you have ordered the OS from 3ds-flashcard and haven't received your key yet you can ask them for it in the order message. I asked them for a ETA for the key and they replied back with the key within 6 minutes of asking them.
You can just get Xecuter SX OS if you own a USB-C and jig, no need for Xecuter SX Pro if you don't mind installing from a PC, android or whatever you have.
I contacted Team-Xecuter to see if you need the Xecuter SX Pro to use Xecuter SX OS and the said.
Got mine from http://www.teensy.co.uk/gateway-3ds-nintendo-3ds-flash-card-cartridge-58.html might be a bit expensive but its true UK delivery from Liverpool with tracking. They are also on the Reseller page of http://www.gateway-3ds.com/resellers/ . They ship the card about 1-2 days after you...