Hi Rody. They do have the dimming effect like the incandescent bulbs. IMO, the most important bulb to replace is under the bony beast ramp - and it's the most difficult.
You can get entire LED kits from Cointaker, but there's probably other places too.
I've only replaced the bulb under the boney beast ramp on my Scared Stiff with an LED, because I like the look of the traditional incandescent bulbs. Can't give too much more info than that