Canham 5x7 Camera with 6x17 back. That gives you 4x5, 5x7 and 6x17 with 1 camera plus full movements.

I got rid of my Linhof 6x17 camera for the canham. Best move I ever made. Also remember that not only is the 617 camera expensive but you also have to buy their lenses and with the linhof you are talking $4-$5K per lens.