I talked to PSC about the vented / non-vented. The vented cap is for off-road use at extreme angles and PSC told me it is not needed for a street car. The non-vented cap is what they suggested for the GN and is what I ordered.
For reference:
Non-Vented for street use:
https://www.pscmotorsports.com/moto...v-8-25-hydroboost-resvoir-hose-kit-21349.html
Vented for Off-road use:
https://www.pscmotorsports.com/moto...reservoirs-overflow-bottles/psc-sr146hor.html
Price is essentially the same and the only difference is the vented fitting in the cap (the off-road version may not come with the black hose kit, that may need to be ordered separately, found here:
https://www.pscmotorsports.com/psc-hk2110-6-10-bb.html ). Again, PSC suggested that I use the non-vented cap. PSC was very helpful when I called. Btw, the silver fittings that come with the reservoir are only stamped China. The fittings in the hose kit however are actual Fragola fittings and the hose itself is Continental.
Working on my conversion today so we'll see how it goes!