Building a Gatton Machine. Need help selecting parts

I bought the bare bones CNC "Kit" from Gatton (basically just wood parts) https://www.davegatton.com/ and the instructions are a bit limited beyond building the physical frame.

First
the Gatton Plans recommend the dumpstercnc.com "Gatton CNC Kit" for the Leadnuts: 1/2"-10 ACME 5 Star, Flanges: .980 Cutdown flange with (2) .173" dia clearance holes, Couplers: 1/2"-10 ACME 5 Start (2 turns per inch),
Gatton CNC Anti-backlash Kit. I am checking to see if a better kit is recommended
($150-300)

Second
I would like a few good recommendations on controller kits (complete)
(under $1,000)

fyi..
This is 100% a hobby for me and I am looking to just learn on this build and see if I like it. I am also Checking to see what size everyone recommends as far as the bed dimensions, would I be far to limited with a 4'x4' or should I go to 4' x 6'?

I highly recommend you review Dave's build videos. There are others on YouTube as well.

You are limited by the length by the acme screws, 4x4 cutting area is possible. The dumpstercnc kits work. I bought the JaviBox which also works. Something that has caught my eye is the https://buildbotics.com controller. Dave recommends a smaller size but I built mine as large as the screws allow and I get a 5x4 cutting area. Good luck with your build.