The New Darkroom Handbook sounds like a great idea, Andy. I've been looking at getting a copy myself - I'm in the same boat.
I am finding two things as I look at darkroom layouts - first, the idea of renting time in a darkroom helps for equipment and workflow, but layout in a group darkroom is always very different than what an individual would ever do. Second, I'm using a Jobo CPA-2 for processing film and paper without a sink. I've run into very few layouts that take a Jobo into account. If you're using trays, there is a ton of info out there!