I agree with Aaron's suggestion of Salina for the 4a site. There should be plenty of rooms for 4a fans and it would open up several other possibilities for the 5/6a guys as a smaller facility/motel situation would work for them without the additional crowd attached to 4a.
some would point out that much of the Wichita Coliseum crowd comes because they can see more than one tournament at the same location but when you look at the success that 321a has had at Hays it seems possible that 4a alone would probably generate quite a crowd.