Encoder Signals

I am building a large gantry flame/plasma cutter.

I'll be using servos with Gecko 320's.

My longest run will be about 18' from controller.

What type of wire should I use for encoder signals?

Shields on 5V and ground or just A and B?

RG45 or Cat 5 twisted pair A with B and 5V with ground?

Should I use ferite beads on encoder or power leads?

The servos I have are low inertia types and power leads
are twisted tightly.

Does this twisting minimize EMI or is it just pretty?


Any help would be appreciated

Thanks

Doug