I would say the best kind would be a big one...
Should be fine in anything that allows for about 4" between beans planted and gives them a foot or so of soil to grow in... soak for an hour or so before planting and really consider getting innoculant for your seed beans (all legumes fix atmospheric nitrogen to feed themselves with the help of a specific bacteria, and that is what innoculant is.) This will really help your plants to feed themselves, which is why organic culture is so important (helps to preserve soil biology; chemical fertilizers kill it).
HG