Griffon,

I doubt that you can cut a curve with any off the mentioned/available pull saws. Simply because the blade is to wide thus wanting to cut straight. If you want to hand cut the curved knee braces you could to that with a frame saw. You can get a variety of saw blades for this type of saw including a very narrow blade, similar to a band-saw blade, which will allow you to cut any shape you can imagine. It will be a conventional saw blade though but it cuts very well.
In the power tool section there is the option of either hand held or stationary band saw.