Hobby Lobby has these you could start with if they are long enough.

http://www.hobby-lobby.com/struts.htm

Machined Hardwood Struts
Much cheaper short pieces (19") of the Machined Hardwood Struts!

These are cut by machine into very smooth surfaced airfoil shapes. The hardwood is either linden or lemonwood. Length of each strut is a little over 19". The chord-width of the three sizes in inches are: 3/8", 9/16", 1-1/16" respectively. These are hardwood and can be used for structural purposes whereas the standard airfoil shaped hollow aluminum tubing types of struts needs internal bracing.

If they are too short, for longer ones I took some spruce and roughed them in on a 4 inch table saw then a little sanding and they are good.