R34 GTR MFD's work in any car irrespective of your ECU. If you can mount it and cable the sensor inputs yourself you can use it.
This thread is about the R34 GT-T/GT-V factory option popup TV set though not retrofitting a R34 MFD to a GT-T.
There are occasionally auctions for all sorts of GT-T interior pieces on Yahoo! Japan and i bet with some patience something like this could be had for well under 40,000 yen. Most likely 10,000 - 15,000 yen as I don't think there would be a huge demand for it in Japan.
Here's a search link:
R34 Interior Parts