I def want to do most of the seed in the milk Jugs. I also have some groovy containers with lids. They're the cheap rubbermaid "Take Alongs" No problem if I want to cut holes in the lids.
They're the largest ones I found. Probably 10" x 16". One gallon size.
I plan on putting my milk jugs in old rectangular milk crates, so they cannot topple over or be disturbed. I think I can do the same with the other rectangular containers.