I've opted for an acrylic tube secondary and decided on black HPDE for the chassis. The tube I purchased is ~3" Diameter x 24" long , so I'd be looking somewhere around 18" of winding for a 6:1 coil length to diamer aspect ratio. This ratio was obtained by the guide at http://deepfriedneon.com/tesla_guide.html. I've read other sites which claim the maximum should be 5:1 and others that state you should be in the  area of 4:1-6:1.

Plugging in known values into TeslaMap, I can see I'd be shooting for a capacitance of around 31.8 nanofarad using a synchronous rotary spark gap. Much reading has yet to be done on my end for the spark gap.