The Makita 5057KB 7-1/4" Circular Saw is a saw with a dust collector that is ideal for cutting fiber-cement materials. It has a 13 AMP motor and can cut five 5/16-inch siding boards in a single pass. The saw also features a dust collection container to reduce dust, dust-proof bearings and switch, and a control lever for easier plunge cuts. Reviews note that it cuts well and doesn't get jammed up.
It also works great for cutting soapstone counter tops.
Retails for around $500