The codes advertised pertain to both the input and output side. The unit stores a code in 3 bytes and then reconstructs it when sending it is required. The NEC codes are used by many other brands and are perhaps the most popular. RC5 is Philips and is also very popular.
The sensor input takes a demodulated receiver, not the kind used by Xantech and others which has a high frequency component that neds to be demodulated. The best way to connect another repeater block to the EZUIRT is to use an emitter placed next to the EZUIRT built-in receiver.
We will be including a receiver and increasing the price of the EZUIRT in a few days.. The unit will also be carried by Smarthome.com now that aour production quantiies have ramped up.