I'm in 100% agreement with Donald! Start small and plan for expansion has always been what I have told newcomers to the hobby. Nothing can be more frustrating than attempting to build more layout than you can realistically handle in terms of time and money.
I have, at one time or another, used just about every track system out there, past and present. Today, with my new layout, I am using GarGraves track and Ross switches...something of a standard these days in the 3-rail hi-rail world. If I was not using that combo, I likely would be using Atlas O track.
The Z4000 transformer I use has served me well over a good long time. I have no real experience with the latest Lionel ZWs, but my guess is you can't go wrong with either transformer.