Since I'm not actually in Portland (Universal Cycles and BikeTiresDirect are local there), I thought I'd see what the local Eugene shops had on their websites.
Two shops, Pauls & Hutches don't list any parts on their website.
One shop (Arriving by Bike) seems to have big ticket items listed, but don't list the little things like bike tubes or chains. They also don't list any prices.
Parts - Arriving By Bike? Transportation Store
In theory, looking at a website, I could decide if a store is even likely to have my order in stock. Hopefully listed items would be in stock and in the right sizes.
Looking at my shopping list above, I don't see any exact matches. There are two other brands of stainless bottle cages that might substitute, and several items that I very much doubt they carry, although it is possible one of the "road" shops would carry the tubulars.
I suppose I could call ahead to make sure they could pre-order my parts and mark them up.
But, I hate riding, say 3 hours RT to pick up items that I'm not sure a store carries.