i just made some more copies...David Wilson, Bicycling Science, on tubing properties (to give me some concrete data on this whole psi thing) and Gail Heilman, The complete outfitting & source book for bicycle touring , from 1980--great pictures and specs on a lot of old touring frames.
i've also rethought some of this bike's purpose.
i've never really done anything that could be described as touring. i do a lot of riding; my bike is my only means of transportation about 95% of the time. i carry a Chrome Metropolis messenger bag that's usually pretty full and sometimes really heavy. and the San Jose is single-speed, so i've got myself in pretty good shape from living like this since January. but it's not the same as packing everything onto a bike and setting out for a few days.
so i envision a progression of bikes. keep the SJ as my commuter/around-town/every day bike. build a practice frame, maybe with parts from a junk bike. build my first real frame, a light tourer for up to, say, a week of mostly unsupported riding--light tent, light bedroll, a couple days of food, a pan, a change of clothes. gradually increase the length of my trips until i reach the point where that frame doesn't do it anymore and i want to go on a real long expedition, then (actually before then) look at building a serious full-loaded tourer.
this light tourer will be a compromise between fast and long. fender and rack compatible, but not for hauling the kitchen sink across the country.
the other thing i haven't really gotten to yet is funding for this project.