If you're not planning on running command control engines, like Legacy, I would start with a single CW-80 or Z-1000 and run a standard buss line with several power drops (feeders) about every 10' of track and see how that works. It should be fine for what you've described. There are many threads on here that discuss how to set that up.
In addition, the CW-80 has a separate outlet on the back that will power your accessories (run the outlet to a 12 port distribution block and then hook your accessories up to that).
If you need more power you can always add another or sell and upgrade to something like a Z-4000.
