Are there breeds that can be sexed earlier than others?

[Eilsel]

General question: Excluding obvious sex-linked breeds like RSL, BSL, and other auto-sexing breeds... are there chicken breeds that can be sexed earlier than others?

Specific case, advice welcome:
I don't want any roosters but I think where I'm getting my chicks there are some breeds that are only available as straight run. I'm planning on getting 2 Barred Plymouth Rock, 2 Golden Laced Wyandotte (both sexed chicks), and have the option for several different types of straight run: Buff or Lavender Orpingtons (original first choice), Lakenvelder, Americana, and others (I think these are the main egg layers though).

Other options that are advertised as pullets are RSL, BSL, Rhode Island Red, Golden Comets, and Silver Laced Wyandotte. My primary desire for chickens is for eggs, I want generally personable chickens, though I don't need them to be lapdogs, just not too terribly high strung or grumpy, and I would like a few varieties of color. Not looking for crazy high production as I would like theym to lay fewer eggs for longer rather than lay a bunch of eggs one year and then crap out on me. Would love your opinions.

ETA: the original question was asked so I could replace any cockerels before the chicks were too big, so they'd still all be within a few weeks age of eachother.

 

[JaeG]

Bantam breeds you can often tell at around 4 weeks old, but larger breeds you'd need to wait until 6-8 weeks before getting an idea of who's going to be what, and even then, sometimes they surprise you. Barred Rocks can be sexed at hatch but only if they have been specifically bred for that trait. Hopefully someone else has more suggestions.