I started a CNC plasma table build about 6 weeks ago Here's what I've done so far. I wanted to be able to cut a 4x4 sheet edge to edge, so my table has a slightly larger footprint. The table will be completely dismantleable so I can stash it away when I'm not using it. At this point I don't think I'll be using a water table. But a downdraft would be pretty easy for me to implement since I already have negative air machine capable of 2000cfm air movement .