Well. I've not seen anyone do a dual trackball, dual spinner panel. The trackball design I'm curious about. I'm sure some folks would be interested in this. Most of the BYOAC folk would commend you for your design ideas, though you'd get a little heckled for its lack of bling.
Ultimately, the number of vendors and their products showing so, most folks want a 'higher-end' product.
(Especially as you haven't gotten any response besides mine here) I recommend you hit BYOAC.
Scifi frauds. SF illuminates.
Culture General Contact Unit (Eccentric)