I bought a 400 buck frame fitted out at the local bike store, they substituted whatever components I wanted, I would be surprised if comotion wouldn't do the same. Of course you need to have the right mindset. You may see a 100 dollar spread somewhere, but if putting your part on the bike is a special order for them (or whatever), the actual spread for them may not be what you see. But if you are fair about it, they should work with you.
I've heard nothing but good stuff about Comotion.
I'm not a tubing snob, I'm sorta a reverse snob. There are claimed advantages to air hardening tubes that I have challenged a lot of people to set straight, and never had any takers. Heat treating is rarely as simple as: "so then I bumped it to 3000 degrees for an unspecified time, then crashed it in an air filled atmosphere, bingo, perfect heat treat." I'm in no way dising these tubes, but I'm not over the moon for them.
I tend to be more concerned with tubing parameters (size vs. wall thicknesses, etc...). I'm not sold on the idea that tandem tubes or even tubing sets are the right way to go for a touring bike. In the curent environment one can construct so many geometries, I'm not sure why people are hidebound by tube sets. Just for fun I ordered some tandem parts, and there is a wide range of forms, some being very heavy. I doubt those will see the light of day on a single. The lighter stuff is trivially larger than normal parts. I wasn't so impressed with the product that it seems worth taking on the limitations of the standard parts. You have tight limits on overall stay length. I kinda prefer the style of frame that takes the geometry of the tandem rather than just swaping in some parts. Anyway rant aside you already have riden these kind of tubes so you shouldn't have much trouble believing in them.
My recollection about Riv is that they are also reverse-snob on tubing.
What Beckman had to say about tandem hubs convinced me the 145s weren't the way to go. Basically the idea being you don't get a wider spoke staying base since the geometry is there to accomodate tandem brakes, not wider staying base. There are quite a few models of tandem hub, DT has quite a few alone, so that may or not be a good generalization. It did cure me of 145 fever. Anyway, I am over on the dark side of Rohloffdom now.
Vs. should give you less bag problems not more, though they can be fidly. I am currently using cantis, but will experiment some more with Vs when I get enough cash for the Pauls. Could be a long wait.
I'm with you on the simple drive train. Sugino and any decent BB are the choice. Though cash permiting I'm going Phil bracket, and some kind of rediculously expensive CNCd single speed cranks for the Rohloff.
I'm not convinced on the white fade look, it kinda looks like a really large seagull got the better of someone. But that's why paint comes in so many colours.