Camaro Wheel and Tach?

[muddpile]

My interior needs a retro update in terms of a tach and a speedo. Before I go treasure hunting at the salvage yard, I have a couple questions.
#1, Do those 70's 4 spoke camaro wheels discolor or crack really bad like the original truck steering wheels?
#2, What is the diameter, and is the rim a decent thickness, or thin and uncomfortable like the stock truck wheel?
#3, What all do I need to install it in my truck and keep my horn function? Just the wheel, horn button and the guts inside?

As for the Tach, I have read many threads on it and know how to install it, but I was just wondering how well lit they are at night? Will it look like it was meant to be in the dash during the night too, or will it be brighter/dimmer than the rest of the gauges?