Those gauges look great! Here's my failed/abandoned attempt to do the same thing - maybe you can get some value out of it.
I tried something similar a few years ago with Speedhut guts (I ultimately went back to factory gauges) I had a speedometer and tach and was going to put the oil, gas, charge, temp under the dash.
There was a trophy/award shop in town that made the gauge faces for me out of color coated clear plastic. He had a laser setup to vaporize the colored coating and leave an image on the plastic. Cost about $100 for the initial setup, but every gauge face was about $15 after that. (i hired a CAD guy off of CL to prepare the file of the gauge face - cost about $100 IIRC) The laser also trimmed the plastic and cut the window for the Speedhut digital display.
Here's one ready to attach to the Speedhut speedometer.......
To back-light them I bought a LED light strip and a dimmer off of ebay. I wrapped the LED ribbon around the inside of the OE gauge can. The LEDs could be white, red or blue. Here's the blue one............
