How about hacksaw blades for double prong tension wrenches? I read a post on here where a member made some double prong (falle) style tensioners using hacksaw blades and salt water etching.
That may be worth a look for you JohnnyWalker. I made two sets, four to each set a few days ago using this method. I have fitted two of them to keyways I'm practicing on and I really like them for access.
With the ease of making homemade tensioners and picks, it allows you to try a lot of different designs without paying big $$ for specialty picks/tensioners. One trip to the local junkyard landed me about 20 old wiper blades for blanks.