Replaced the S bar with a Tioga R60 that I ordered from Chain Reaction so that I could get higher on my Brompton. Added Shimano brake levers that I had in my parts bin. Still need a gear changer cable, so I will have to order that as the Brompton dealer didn't have any in stock. Took it for a small ride and the it seems comfortable, at least more comfortable than the S bar.
You can see the difference in height between the M bar and my conversion. It is pretty close.
The fold. The bar is pretty close to the ground but it just clears.
Everything needs to be tweaked but so far a success.