except the GEMS dash units cost fucking £3k for a semi reasonable sized TFT unit!!!!

When you are talking that kind of money, you are better off buying an off the shelf hardened PC based car computer, and paying someone to set it up so the dash page of the M-TECH ecu comes on automatically on ignition start up etc.

And i could have much much bigger than a puny 5.7" TFT!!!

It just needs the software package to be intelligently written - most mapping software or ECU interface software has a basic "dash page" just make said page more customisable, or have a cut down version of the software just for the dash.

Hell look at most high and mid range cars now, full TFT dashes with digital dials the lot run through canbus from the ecu. Background just needs to be a bitmap which can make it look fancy as hell when in reality it isnt necessarily so fancy in implementation (nor does it need to be).