May I suggest looking in to VDO gauges. I took this route a few years ago with my old 32 GTS-t as I always wanted a stock OEM look. (I hate the space ship bright light cheap gauges)
VDO are a quality brand and easy to find. Sensors come with the gauge, you'll just need to pick up a single din slot 52mm gauge holder (Anywhere online/ebay) and wire you're selected gauges in accordinly.
From memory the stock gtr 3 gauge cluster harness runs with the dash loom. Massive pain in the ass to disect and install in to 32 GTS-t considering volt and another boost gauge would be pretty useless.