From memory I believe that 8 is the most you can get from a single switch, so you could then insert a 2 way manual switch for the two banks.
If you look at some of the earlier posts there is quite a bit of information on the torroidal dishes, not least the fact that they are not quite as efficient over the whole arc covered. There is also a problem due to physical limitations in spacing of the LNBs.
Oct-Nov/01 edition (just out) of Tele-Satellite international includes a write-up on the 90cm toroidal dish, which was tested with a bunch of the new Alps mini-LNBs. Very positive test. Beautiful bit of kit.