hey Doug, I think Quanah should make for a fine layout theme, especially by beefing it up a bit in terms of making active the inactive industries in the area.
I really don't want to embellish too much or step too far outside of the 2005 timeframe. I believe all of the industries that I identified above are in play or at least within a few years prior. I have considered including Altus, since it also would tie in with the WT&J from Wichita Falls. But that would definitely be at best a "Phase II" or more likely III or IV.
I picture Quanah being very similar to Emigrant on your layout, with the Burns Branch being the Altus Branch, and much shorter and more sparse trees.
Layout/LDW-wise, I've just had a dickens of a time trying to figure out how to capture the essence of Quanah without it taking up so much real estate. I go back and forth to a "no wye's and wrap the yard around to (roughly) parallel the main to the left" (which allows the Cotton Seed complex to be mostly a backdrop structure) to having the entire yard on a center peninsula and some sort of turnback to staging. My best "middle ground" effort so far has been the aforementioned dogbone style plan, which I'll try to post when I get a chance. It is a bit on the "suspended reality" side of the fence, but it lets me at least run some trains and start working on structures and eventually the helix and staging.