I started with a setup very similar to Craig's but my legs are too long to comfortably use the pedals. So I went back to try and improve the stock setup. Here's a few pictures of what I did.
The first thing I changed was the idler arm. I moved the attachment to the rear pedal push rod up 2" to get the same mechanical advantage as the front pedals.
Then next thing I changed was the diameter of the push rods. I increased the diameter from 3/8" to 1/2" to increase the stiffness and reduce the chance of buckling.
The third change was to get rid of the snap bushing that is used for the push rod guide and changed it to a plastic spherical bearing. This got rid of any slop and binding the stock set up had. The picture of the bracket above was the prototype and has been changed slightly to better match the stock geometry.
The last modification I made is one that I think makes this set up (modified or stock) much more effective. I added a folding shelf that can be used to fill in the foot wells when there is a pilot in the rear seat. The shelf attaches to floor at the rear of the foot well and folds up so the foot well appears stock. When it is needed, it can be easily pulled up and automatically locks in the up position by dropping a leg down into the crotch of the foot well. When not needed, it is pulled up slightly and the leg is folded back and the shelf drops back into the foot well. The shelf greatly improves the ergonomics of the stock set up and I think makes the pedals more comfortable to use.
Here's a short video of the shelf.
I can make any of these parts for anyone interested. Just PM or email me.