Another benefit of single disc/caliper: less unsprung weight!!
+1. Nice pads on that and it does a great job, other advantage is less gyro for steering purposes. Makes the bike feel lighter than it is with regards to turn-in.
I think the single is nice, but if you are looking for making it doubled up, you'd need:
a) Second 320mm rotor. You probably want one that matches.
b) Second Goldline 40mm-mount, 4-piston, 2-pad, 1 pin Caliper
c) New Brake line with T for second caliper, or 2nd brake line and double line banjo bolt at master
d) Banjo bolt at caliper
e) brake fluid
f) re-balance wheel
Can't remember if single front rotor Brembo master is a different part #, but if it is, that would indicate it has a smaller piston, and may not sufficiently push as much fluid for two calipers. I know the aftermarket Brembo race master cylinders indicate 16xYY for single front caliper, and 19xYY for dual front calipers (YY being pivot, say 16x16, 16x18, 19,18, 19x20, etc)
