My wiring is a mess, I’m ready to do something about it. I have no clue about cable chain. Should I be looking for something specific, or is it all the same?
The cnc is 30in x 18in.
Go the next size bigger than you think you need.
I am now looking at my 3rd set of cable chain as each time i think that i have plently of room then i think well why dont i add a …, air line, extra power for a laser … and then it dont all fit.
I am liking the igus zipper chain that can be found on ebay. Still pretty expensive but when you realize that you need to add in one more cable just peel back the cover and add in.
On my 50cm x 50cm I used 10x20cm chain, and now I wish I would buy at leest twice bigger 
3 motors, 4 endstops(3wire shielded cable), spindle motor.
All wires also in brided mesh.
I built my own (assuming we are talking about the same thing). Inexpensive (scrap wood), durable, fully functional.
Me I use this, (2 units)
CNC 27x27x12