Let me preface this response by saying this is how I have my little setup done. It works very well for me however, it is not the end all, be all way of doing things. I operate both original and modern standard gauge trains with no issues.
I am using a MTH Z-4000 for power. I, like things to be as simple as possible. Cannot get much more simple than 2 handles. Push buttons for direction, bell and whistle make me very happy.
As for track, I used USA Track. In my opinion, it is the best out there and Kirk is one of the best people to do business with. I used 16 gauge, stranded copper wire soldered to the bottom of the rail. This way, there are no unsightly wire connections to be seen on the table top. Those feeds are placed every 4’ throughout the layout. With the tight fitting track from USA, I probably did not need to put that many drops in however, my layout is portable so I did this due to the moving and vibration of transporting.
Looking forward to hear from others as to how and what they do.