Bummer, that walkthrough on dreamwidth.org was a good one. A bit dated now though. You might want to check youtube for some video walkthroughs. Generally you want the enclosure to be 4x2x2' or larger. I would put ventilation low on the cool side and high on the warm side to allow a nice current to move through it. You could set up a sliding door on front, or a drop down door with hinges on the bottom and a lock on top. Using melamine is cheap and easy to clean but it's very heavy so I would use a decent plywood that is untreated. Then coat it with something to seal it up like paint or polyurethane. A screw socket on one side for the basking light should do the trick. You could hook that up to a lamp dimmer so you can easily adjust the output. I would use a 22'' T5
UVB light and set that on the top on the same side as the basking light. You could set it along the front or back or even at a diagonal to provide a good UVB spread over the basking area.