Sparkfun Serial Enable LCD Packback w/Keypad functionality

I'm planning to use this Serial Enabled Kit from Sparkfun, which is actually a separate Arduino chip working as the LCD driver. I will use Hardware serial from my primary UNO to communicate with it. I have a 4x4 keypad next to the LCD, and want to have the LCD backpack take care of that, too. I'll be using all custom PCBs w/SMD components. I am wanting/needing a very reliable/solid connection on this project. I've seen some wires looping thru a ferite ring to cut down on interference. I'll have 4 wires going from my primary board to the LCD backpack board, at about 12" long. +5V, GND, Tx, & Rx. Would it benefit to run them thru a ferite core like this one?

To connect this keypad to the LCD backpack, I'm thinking of using a stock 6" ethernet cable. It'll give a solid locking connection, and won't be as fragile as the 8 pin header on the back of the keypad. I'll just make a small board that solders to the back of the keypad that connects the pins to an RJ45 Jack. |500x500

Durability & long life is important in this project. Does anyone see any issues with this setup? It'll be enclosed, and in an indoor environment. Thanks.

You could use the same cable and RJ45 to connect the keypad and your UNO to the LCD. At 5v levels with no differential signalling using just simple twisted pairs like in Cat5e or CAT6 you could probably get 10ft or so sending serial data at 9600bps. I personally don't think you will have any issues with 1 ft. Just be sure you pair the transmit and receive with a signal ground in each.