Gauge & Switch LED Mods

So I was thinking about this one for a while, and I know the next thing I want to do, other than what I need to do. But to my mind, I have unanswered questions.

On the gauges, do the bulbs have the rubber sleeves over them for the green, or am I going to find all of my coloring to be in the gauge face itself?

If it's a coating or film in the gauge face, is there a way to remove it, or scratch it off, something to allow the color of the bulb I'm using show through?

For the indicator lights, I repeat my last question.

Is there a separate light source for the needles, or do the needles get their light from the cluster lights?

If I see this is going to take a long time, would I be safe to buy a used cluster from eBay to do this with? Could I use this cluster straight off, or would it have to be reprogrammed to match my truck?

On switches like the power windows, headlights, locks, info center, and A/C and Heat controls, how much trouble will I have changing all these over to LEDs?

Another option I am considering is just buying all the parts that I'm going to relamp from eBay so that I don't have to keep my truck out of commission for too long.

Also, could I replace the lock switch by the liftgate with one that is lighted?