Wire Size & fuses for solar install

Ok, so much for doing this on the cheap. I found this combiner that will accept inputs from the MC4's. Looks like I would mount this on the roof and run two 6 AWG wires, one positive, one negative, from it to the controller. Sound right?

http://www.solar-electric.com/misomnsoarco4.html

Which fuse between battery and controller?

Thanks for the inputs.