They are called "vernier" calipers or as the old timers call them "very nears" because that is what you have to be to read those buggers . All of my mics are vernier style and so are some of my calipers.
On the drill bits, a full set of number, letter, and fractional are nice but I would research it and find out exactly which sizes you will need and spend the money to buy good American made bits. It is amazing how far off the cheap chinese bits can be. I recommend something like Chicago Lathtrobe (SP?) or Cleveland Twist and I prefer the split point bits as they don't "walk" around near as much if at all. You're going to want your trigger axis pin holes as snug as you can get them and you will find that spending a couple of bucks on a good quality bit will pay off big time in the long run. Look over at Enco, MSC, McMaster-Carr, Rutland tool, or go to the links page at mini-lathe.com. They will have a multitude of places where you can look at this stuff. In a pinch your local Sears will have what you need too.