So prior to receiving my kit, i need a table to build it on.. thinking some kind of simple plywood torsion box, but it cant be too "solid" since it needs manhandling in a narrow doorway, and on a flight of stars. However, how flat does the table need to be? I dont want to build in any wonkiness. I ask because not having a giant, perfectly flat table, on which to build my giant, perfectly flat table, im not sure what tolerances will be possible..id be relying on someone else to cut the wood and I have a tiled floor on which to work. A 100 year old tiled floor made of small tiles. Its not the flattest. How do people generally approach this...? Am i worrying too much!?