My guess on the idiot lights? Way...way off. As far as the wiring goes, I think the best way to go about that is go to a junkyard (once you get back that is), find a 'Stang, remove the dash and clip off the first few inches of wires that lead into the connector that connect to the back of the cluster, so now you can just run jumper wires from your stock harness into wires on the back of the 'Stang harness.
I highly doubt that it'll be a straight bolt in, even if the shape is close enough to make it look like it'll work, you'll probably have to get a little crafty on the mounting.
BTW, you lookin at the Dakota Digital dash for the 'Stang?