If you ordered a Sky3DS you can put OOT or CN onto Sky3DS and use that exploit from Sky3DS. Your N3DS needs to be 9.2 or lower.
No need to buy OOT or CN since you already have Sky3DS.
So basically:
Sky3DS + OOT ROM/CN ROM>GATEWAY 3DS/NINJAHAX>total access
Gives you the option to either use NinjaHax or GW. Your choice. I'd go GW for usability.
Hope that helps...