For a long time I was using King Arthur bread flour, and I liked it and could buy it locally, but once I got over the concept of paying to ship flour, I tried the KA Artisan Flour, and I found I could get more loft from it. Interestingly, the Artisan flour has less protein than the regular bread flour. Looking at their various flours, I suspect it is just a mixture of their regular unbleached all-purpose flour and a small amount of their White Whole Wheat, which would be a lot less expensive to mix oneself than purchasing the Artisan Flour. The White Whole Wheat is a bit softer than their regular whole wheat. Next time I order from KA, I'll get the WWW and see if I can replicate the results with a mix of around 1 part WWW to about 4 or 5 parts AP. Here's a photo of a typical loaf-- The AP and WWW both come in organic versions, so that might be of interest to you. I've been trying to get an earthier sourdough, and I've found even a very small amount of dark rye flour completely changes the profile of the bread. The proportion that has been working for me is 1/4 C Bob's Red Mill Dark Rye, 1/2 C KA regular Whole Wheat, 1/2 C KA Unbleached All Purpose, and about 2/3 C starter for the poolish, and then 3 C KA Unbleached All Purpose for the main dough. I'm also using 1/8 tsp. of ascorbic acid powder and getting good loft and a chewy texture and tangy flavor with a hint of rye. I haven't photographed this one yet, but next time I make it I'll post a photo.