if you need a galvanic isolated, easy to build CAN Board, here it is:
Either use DCDC converter to generate isolated 5V or 7805 with external supply.
KiCAD and Gerber files are included.
Use this link:
http://dirtypcbs.com/store/designer/det ... 5-v1-1-zip
to get some boards and share the stock surplus with other CANBus wizards
PS: there is a little fault on the PCB - if you need the 7805 you have to solder it on the other layer ...