Burning
Code80 flextrack and turnouts you have on hand for the mains and primary branch trackage is a realistc way to go. Leaving lighter rail to the sidings and furthest reaches of the branch would be common SP practice. Adding a simple fascia and push/pull turnout controls keeps the budget in check while avoiding the hands on the layout that always damage the best details (and the hardest to repair) on the layout...
I have some Code 55 turnouts and rail, Going to pick some more for the branch. As soon as the rain lets up, going to grab some of the ballast of that branch and bust it up with a hammer and screen filter it. Going to try to do this layout with the least commercial products available - Avoid Woodland Scenics and Walther Cornerstone. Scenic material will be real dirt sifted fine and the structures will be scratchbuilt and backdrop portions. OH - Tivo, on the backdrop, going 12" from roadbed to lighting valance. Painted a deeper blue - Stenciled clouds and will try to give the Valley impression on the b/drop.