I have made two bows from cypress boards. I like the wood alot, it is similar to Eastern Red Cedar in some ways. The first bow was wide and flat, I backed it with canvas. It was a short bow (48" long) and was 2 3/8" wide, and 3/8" thick with "pyramid" shaped limbs. It pulled 42# at 20". I sold that one, but took no pictures. The other one was 1" wide and about 48" long, sinew backed, and it failed miserably (I should have known better!)
I think this wood will do nice bows, I'd love to try it again with a long stave. Good luck!