Ex pres - thanks so much for the easy to understand and speedy advice.

Advice on headsets for threaded stems?

When I ride fixed, I only run a front brake, so a mix of canti and caliper wouldn't be an issue. I've found modern dual-pivot calipers to be quiet impressive in comparison to even higher-end 70's-80's calipers I'm accustomed to. Could calipers be as efficient as cantilevers if I used season-appropriate brake pads?

Advice on headsets for threaded stems? Frame protection?