The term daito commonly refers to the katana, not something longer than that. The wakizashi would be a koto or kodachi, and daito and kodachi together are reffered to as daisho.
Depending on the length and period, there are many names that could be used to refer to longer than usual swords. O-dachi would be one, so would choken.
One style that uses such long swords would be the Kage Ryu. However, finding instruction in such a style in the US is probably near impossible. These things are learned in Japan, pretty much no way around it.