I might be able to help with electronic boost guages. Ive recently installed an electronic Pivot boost guage in my r32. Dont have any photos though.
Basically, its all the same, Except the air line that plugs into the back of the guage plugs into a pressure transducer instead (looks like a little black box). Try to place the transducer as close to the source as possible (keep the air line short) to improve response, under the dash is good as you dont want it under the bonnet (too hot) and it cant get wet.
The transducer needs +12V power, negative and has a signal wire going from it to the actual guage. The guage itself will need +12V power from the ignition, +12V from the lights and a negative (or earth).
The easiest place to get all three of these is the cigarette lighter.