you guys are retarded, there isnt anything wrong with running some LED white lights under his truck as puddle lamps which is what i am guessing he wants to do.
CRED, you can tap into the overhead dome light circuit, they will turn on when your dome lights turn on, for example, when you unlock the truck via the remote, or when you turn on the domes via the headlight dimmer switch. This is the same circuit that runs the puddle lamps on the heated/turn Plamp mirrors, the cool thing is the LEDs will also do the theater light feature when ran on this circuit.
As far as your mirror question, the higher end mirrors have the same plugs. They will plug right in to your truck, but your truck will probably not be wired for the options.
Turn signals are pretty easy, as is the Plamp (same as above) The heat on the other hand is wired into the HVAC system and usually requires a AC/heat switch swap in order to wire up.
Some XLT trucks are prewired for turns, not many are prewired for heat or the Plamps.
Just check your plug at the door side and see how many wires you have going into the mirror side.