Here's a few cheap suggestions:
Use an old car rim spaced an inch off the bototm of the drum and fold your chicken wire in the bottom of the rim. Looks like the inside of a BGE eh!
Cut a 2" exhaust in the lid and get a sheet magnet to cover it when you're eating!
Cut a 2" intake and use a sheet magnet to control that
plug the rest of your little holes. This isn't the only way but I think its the cheapest for you.