Adding RFID Reader

I’ve previously mentioned the project I’m working on and promise I will post it when I have it done. However my field of study is primarily computer science so my electronics knowledge is limited.

I’d like to add an RFID reader? Since the GPIO pins are primarily used by the brickpi, I imagine this pretty much rules out the existing boards I could use as a reader?(eg adafruit nfc)

I’ve found a usb nfc reader that works with the pi. However I’m wondering if there is enough to power it,the brick board and the pi. It does normally work with the Pi from what I gather.
http://thinkifyit.com/tr-200.html