There hasn’t been anyone who has implemented NFC on the forum that I recall, but I personally think that if I was going to do a real RFID project now, I would go down that path… since you have to buy a reader as well as an appropriate card, why not buy something that will cover off both bases, and will allow people to use their NFC enabled smartphones if they have them rather than carry and use another swipe card. So from that angle alone, I would go with the Adafruit one. The Parallax one and the SparkFun ones are RFID only it seems, and the Adafruit one has an aerial etc all pretty neatly part of the board. Plus it has massive overkill written all over it, it does UART and I2C and SPI, you name it 
T35 is the current state of play with touch screens for Gadgeteer, it’s resistive touch too. There’s talk of new screens in the works but no detail worth betting on just yet - and again, this is mainly to prove your concept, right? Prototype on that and sort out what you need in practice if the POC goes further.
So lets recap what we’re expecting to assemble here. The device will have wired ethernet and be using PoE to get it’s power. It will have a visual display. It will have RFID/NFC reader.
All sounds pretty achievable.
Components I’d consider looking into:
- a “fake” PoE solution until Architect starts offering his module via http://wiki.tinyclr.com/index.php?title=Community_Offers. Something like http://www.ebay.com.au/itm/PoE-Power-Over-Ethernet-Injector-Splitter-Adpater-Cable-/300667007914?pt=UK_Computing_Networking_SM&hash=item46012673aa.
- you need extender modules, it’s worth getting a few. You need to have them (and you’ll need to solder them) to get the RFID reader working.
- The code from the RFID reader at Seeed studios might also be worth looking at for the RFID reader you end up with. http://code.tinyclr.com/project/445/fez-driver-for-seeedstudio-serial-rfid-board/ is the driver, I’ve used it for one of the serial 125khz readers and it seems to be OK.
- you need to have the schedule info accessible over HTTP/HTTPS, if you don’t have that already then you better get on it
looking forward to seeing your progress