Thanks, this is great. I have an old Antec Solo (in the current, slowly dying server) that I was gonna re-use, which does not look optimal for the SS-400FL2. The SSR-360GP would have to go in upside down.
For the original SOLO, i would go with G360, its cheaper by half, as CA_Steve said, the difference will be very small at low loads where your server should be most of the time. And the original SOLO dont have a the top vent, Seasonic asks for all their fanless PSU for it to mounted with the holes up, this is fine on the SOLO II as it has an opening on top, but on the original SOLO, it will be against the closed top of the case, you would need to have good positive pressure to force air through the PSU to cool itself, for all this i feel the G360 with its fan always on should be better, as long as your case temp isn't very high, it should be quiet.