I want to build a cnc router for processing marble (engraving with diamond tool + water)

I have found this kit https://www.ebay.com/itm/DE-20mm-Squ...0/253786153216
Is it good or crap ?
Can i find in europe a kit like this but bigger dimensions ? for example 1500mm x 1500mm ?
I have found in ebay ballscrews 1500mm but not square linear rails 20mm 1500mm length.
Thank you.