At summit racing.com...
...for the gauge, cup, and tubing kit. It came out to about $60 with S&H. The tubing kit doesn't come with anything to make the "T". I got the brass one in the picture at Kragen and the fittings to go from the rubber to the nylon tubing at Orchard (OSH). You'll also need some wire and connectors for the electrical. The gauge has two flat metal tabs sticking out the back (spade connectors?) and the connector behind the radio has the female equivilant.... about 1/4" I would guess.
I didn't get any vibrations at first, but now I'm getting a little. I didn't tighten things up too much for worry of cracking something. I'll probably end up taking it off and putting a sliver of electrical tape between the column and the cup as padding and then put some locktite on the screws to keep it snug.
All-in-all, I'm pretty happy with it. I'm new to turbo charged cars, so I don't have a feel for how accurate it is.
Hope this helps,