For headsets, I have a few criteria that I look for.

• < $50 (or so)
• Aluminum Alloy Cups
• Cartridges (for now, may go back to loose bearings later).
• Cups should be designed so that they shed water rather than trapping water.

I'm not stuck on any big brand names, but I'd tend to some brand rather than no brand.

One problem I encounter is a limited selection of 1" threaded and 1" threadless headsets.

One recent build has a Ritchey Scuzzy Logic (1" threadless, sealed cartridge) headset.
My current build I'm working on will get a Stronglight headset (1" threaded, sealed cartridge).

Of course, one of my concerns is that I'll get a headset that I'll never be able to find replacement parts for, and will have to dump the whole thing.

I don't believe headsets really affect pedalling resistance, although perhaps they affect stability.

Bottom Brackets?

Hmmm, too much variety to have a favorite. I do like the Campy Ultratorque. Even with the Ultratorque, I'm wondering if the SR are missing seals that the lower ones have, and thus a Chorus or similar may have better longevity.