Flying Monkey:  I was excited to stumble across your thread.  I am also looking at the options of breeding rose comb birds.  We're in zone 4, and planning to build a larger coop this summer that will allow me to keep a rooster, so I can dabble with genetics a bit.  This spring, I got 3 RCBL, and 3 Dominiques.  All were supposed to be pullets, but if my early guessing proves accurate, I have a trio of each breed.  The doms are not any thing to brag about, but at least it's a starting point.  So, next year, I should be able to breed some BSL from these 2 breeds, as well as straight Doms and RCBL.  I also have some EE, one of which lays a beautiful colored egg, and would love to see what comes of her x RCBL.  I'm rolling the idea of working on an auto-sexing rose combed breed, starting with the gene pool I have. Sounds like you're ahead of the game, starting with the leg-bar.  I'll be following your progress closely!
 
How do you find the behavior of the RCBL, compared to the more traditional DP birds?  (RIR, PBR, Wyandotte)