I found an old pizza pan in the cabinet last night. It fit perfectly into my firebox. It has vents in the bottom. It's not a basket, but it raised the level a few inches. At least my ashes won't build up and choke out the flame. I'll try it out this weekend and let y'all know how it worked.
I also bought some 10 inch aluminum flashing, rolled it up into a tube, and stuck that in my smoke stack. It lowered it to grate level. Then, I cut another 10 inch square strip of the flashing and made a baffle. I crimped the top edge around the ledge that my charcoal grate hangs on in the smoke box.
So, now I have a baffle, a lowered smoke stack, and a charcoal basket, all for about $16 in materials (counting the tin snips I bought). I'm excited as hell. I'm going to smoke some St. Louis ribs and a corned beef brisket this weekend. I think it's all going to work well.