elenasgrumpy,
Another thing you can do for a building board is get a hollow core door. You can get a 2'x6' door for about $15-$20 normal price, but if you ask them for a damaged door you can get it for less than that. Then use 3M 77 adhesive spray to attach a ceiling tile to that, or you can use sheetrock screws if you want to be able to change the tile down the road. This will make a great building surface that will be very level. You can bring it out and lay it on your kitchen table, but when you need the table you can pick it up and move it out. If you're doing a good job with your build you won't have to worry about your work falling off because it's securely pinned to the work surface. Doing it this way you have room for the bigger wings or fuselages. Or like I used to do, build several assemblies at a time.

Just something else to think about.

Ken