This is not a build thread but all the info is here: New Linear Z - Rev 2 - Now updated for easy tram adjustment
See first post for parts.
I used generic 6061 T6 plate for mine, didn’t know it should have been leveled and, ideally, stress relieved. Result was not flat, required shimming and hand finishing to make accurate. PITA. Use ATP 5 from Midwest steel supply. It’s cast, flat and stress relieved. And, actually cheaper then the stuff I sourced from McMaster-Carr. McMaster is a great source for nuts, bolts, washers and so on, I used SS hex head cap screws mostly.
https://www.midweststeelsupply.com/store/castaluminumplateatp5
The ball screw is non-standard, just include a drawing when you order it. I think AliExpress is probably best source for all parts now.