Not sure how many board companies for definate, other than Glyde, Early, FSU and Norfin, but Sturgeboards, Sakamoto, Sparks, OBR and VOG build a mixture of Streetluges, Buttboards, Aero kits and G Bikes.
I know this may not be exactly what you wanted Speedy, but just trying to give you an overall look at gravity vehicle manufacturers.
There are quite a few guys privately building there own vehicles for various disciplines as well....good quality equipment.
Mate, i grew up in townsville (NorFin base). Cre8ive Sk8 up there is an institution, and Adrian (owner) is a local legend. His mate Paul is the mastermind behind NorFin shapes. When i was after a new board Paul took the time to get to know exactly what i wanted.. how heavy i am, riding styles, flex preferences, wheelbases. You name it. I can't recommend them highly enough; they just know their shit and if you come to them with a new idea they'll love you for it, what i ride now really is *my* board
jump on google, norfin and cre8ive are both there.. have a chat