I've read bibles on joystick mounting techniques of recent, and never realised there were so many options, I've chosen this design, courtesy of Slagcoin a highly recommended detailed Joystick building resource I use.
I Chose Retro style Joysticks, as I think there visually appealing with there chrome finish, and industrial grade metal components as opposed to the solid plastic option. The Resin knobs are interchangeable and simply screw off with a brass internal thread. I ordered mine off a reputable power seller on eBay, you should be able to purchase them for around $20.00 AUD each including postage.