Yes you can get sunflower plates for planters also. If you are looking for the easiest that will plant what you listed then go with a planter. There will be less figuring that goes with it. You may have to purchase several plates for each variety. Different sized seed requires different size plates. With beans you could make the first pass then come back and split row (plant another row between existing rows) to get a narrower row for canopy closure.

Like hossdaniels said there are many more options available with some drills. You might even want one of each.