I think the purpose of the choke tube for the 45-410 is to stop the spin on the 410 shot wad as it is flyin down the barrel. The spin is caused by the rifling for the 45 colt loads and the choke stops that.
So, I don't know what you would be looking for in another choke size. I don't know of another size, and I don't know if I am helping you out here or just telling you what you may already know.
Dave.