nun said:what about hubs the Shimano LX and XT will work just fine, but is it worth going to Shimano XTR, White Industries or even Phil Wood?
I think I'm settling on the best possible Shimano MTB components as I can afford for the drive train.
What is the spacing of the rear dropouts, inside to inside, on your Circle A frame? If it is 130mm, you can use a Shimano road line hub, like 105 or Ultegra. If it is 135mm, you can use their mtb hub line, like Deore, LX, XT. I don't know about the spacing requirments of other brand's hubs, but maybe they too have 130mm road hubs and 135mm mtb hubs. If Circle A is building you a road frame, they might think you want 130mm rear spacing, but if you want a LX or XT rear hub, I think you need 135 spacing.
It is my understanding that anything better than 105 or LX is only better in weight, and not by much, especially for tourers other than ultralighters. At least with Shimano, I don't think the price increase of higher end components brings better quality, performance or durability.
Also, since your largest cog will be 34 teeth, you might want to check with Circle A about the length of your derailleur hanger. On my old '86 Trek, I tried using a Shimano Nexave cassette with a 34 cog and I used an LX derailleur. However, the derailleur pulley guard hit the 34 cog when the chain was on that cog. Ended up my derailleur hanger was too short, even when I loosened the derailleur's barrel adjuster all the way. Had to switch to a 32 cog.
Does Circle A know you need a derailleur hanger that will be long enough for a 34 cog? Do they know you want spacing for a 135mm rear hub?