No need to match the FCC code of the key to work? 
From my understanding, Nissan won't design a remote control with transponder key for "specific" car model. As long as the remote control is similar to your stock remote control (or you prefer same FCC), it can be work after they "authorized" it via computer (OBDII programming). The most important thing you need to take care is.. if you purchase the key from ebay, the key must be a "Transponder Uncut Key", which you also need it to be programmed into your car's immobilize system via computer (OBDII programming).
Purchase iKey from ebay, what you need to do is
1) Purchase the iKey with Uncut Transponder Key from ebay
2) Once received, go those key maker stall to cut the new key with your existing key
3) Bring all your existing Keyless Remote Control (with key), existing spare key, and the new Keyless Remote Control+new cut transponder key to TCM (or other workshop with OBDII programming skill)
4) Done.
