I have mine mounted in the dash.
I bought the egt sensors off the guy who supplyes the guages,they are about $60 each.
You can either use VDO sensors or calibrate your factory sensors.
I used a VDO oil temp sensor and for the boost i used a bosch 3 bar map sensor to read the manifold pressure.
If you are running lowish boost you could use a map sensor off a turbo road car but if you are looking to up the boost you will need the 2 bar or 3bar bosch type.
A 2 bar sensor allows you to read 1 bar (15lbs) of boost and the 3bar sensor allows you to read up to 2 bar(30 psi) boost.
They also run on 12-30 volts so they are great for 24volt vehicles.
Here is a link to my build.
Sorry no picture of the guage mounted.
http://www.offroadexpress.co.nz/builds/ ... twin-turboHope you like it.