You can use PTB port for connecting a LCD display to SRB board (pins 19 - 26 on J103 connector). NCB board use the same port for connecting LCD display.
If you have 6 outputs left, you can use a "standard" 16x2, 20x3 20x4 LCD. The link shows one from sparkfun. There are very common. You can also get it with a serial interface if you have a port left.