Dude I am really liking this! I went a different route though with mine. Here is my smoke grey controller modified with PS4 thumbstick.
However I am combining the controller with all black back controller parts from an R7 Dreamcast Japanese exclusive console to make something that will match my custom case I recently ordered here.
I also have the Brook Wingman SD and got a matching Saturn 2.4ghz wireless controller from Retro-Bit to go with it.
You can follow my build here.
viewtopic.php?f=2&t=16858