One of the more economical choices would be a 2 foot by 4 foot sheet of 1 inch thick particle board that is then topped with a 2 foot by 4 foot acoustical ceiling tile. Use the type of ceiling tile that is solid, without the small holes in it. You can use spray adhesive to attach the tile to the particle board. You can then set this up on a sturdy table and have a serviceable build board. Other choices would be a luan door, commercially available build boards, like the ones from Great Planes, or you can go with a magnetic board like the one described on Caffeenman's website, airfieldmodels.com.

If you work with pins, get stainless steel Tee pushpins, available at your lhs, or online. I would also recommend a tee pin tool. These will save your fingers when pushing pins and will also give you leverage when removing pins.

Scott.