There's a guy on the mk5golfgti website who sources these units. Fitting is a bi awkward but if I can do it, anyone can.
Stockton On Tees, im after £480 and will help with fitting and coding etc. It has latest firmware, shows speed limits etc. It has latest maps with speed camera locations etc.
The GTD is like a blow up doll. The GTI is like a proper woman. Sure the doll might last longer, and the woman might have higher running costs, but which would you rather have?