Bob, that's great that you've found a good chair!
I'm going to add my voice to the chorus of those talking about the importance of ergonomics.
The key with monitors is to be eye level - you shouldn't have to tilt your head or eyes up or down.
If you are using a laptop without an external monitor, you can raise the laptop and get an USB keyboard+mouse for under $50.
Ideally your wrists (when typing) should end up lower than your elbows, so a below-desk keyboard tray/drawer makes a lot of sense.
In terms of biomechanics, it's healthiest for your pelvis to be tipped slightly forward (a position forced by the kneeling ergo "chairs.") Many years ago I was in a bad car accident. For the next year after the accident, I had an office job in front of a computer all day, and I sat on one of those big inflatable yoga/pilates balls instead of a regular office chair. It really forced me to be "aware" of my body while at a desk all day, and was far better for me than a regular office chair.
I find that when I have to spend long periods in front of the computer, creating awareness around proper pelveis and shoulder position makes a workld of difference in fatigue level and shoulder soreness (or lack thereof.)