I plant millet with an old MF grain drill. You want a lot of seed down, and I have no problems getting the old drill to put out what I want. The small seed attachment would also work, but my drill doesn't have one.
If you can find a couple of old Planet Jr. vegetable planters, they will do a better job than anything else I have found. As suggested, you can also do a good job just broadcasting the seed and lightly discing. I have done this by mixing the seed with the fertilizer when I spread it.
Last year I planted a dove/quail patch with the old MF drill. I filled one side of the drill with grain sorghum and the other side with browntop. Each side of the drill has its own adjustment, and I was pleased with the results. Planting a dove field ain't rocket science, and most any way you can get the seed down will probably turn out good.