Best you can get is a dual LNB bracket, I use one with a Ku LNB in the main focal position and a DBS LNB on the side bracket works GREAT, they can then be hooked together with a 2/1 DiSEqC switch or just two cable runs!
(I am also working on a "double dish" it will have Ku band and DBS LNB pointing at the SAME SATELLITE at the same time (need backers))