Is the SparkFun Transceiver Breakout - nRF24L01+ (RP-SMA) unit compatible with other NRF24L01+ transceiver units? Do I need to have a SparkFun receiver and a SparkFun transmitter?
Larry
Yes, and the command set is also backward-compatible with the original nRF24L01.
They don’t necessarily need to both be SparkFun products, but ours are better and can definitely save you some headaches.
The main thing when selecting the RP-SMA version of the board is to ensure you get an RP 2.4GHz antenna 
Hope this helps!