Fast boy do you want an actual ECU remap or just a tuning chip, i.e. magic black box?
http://www.cartuningclinic.com/ these guys seem to be based near Edinburgh.
Also you might want to have a look into this:
TDI-Tuning - Hyundai i30 1.6 CRDi Blue Drive 108 BHP / 110 PS / 81 KW / 260 NM / 192 LBFT Tuning Box SystemI guess that's for your car, isn't it? My colleague has got an Audi A7, and he's had it "black boxed" from tdi-tuning by for 13 months, done 23k miles, no issues and he's very happy. Apparently their tuning boxes don't just send false signal to ECU so that more fuel is injected (which f*cks up your DPF as result), but also modifies the air flow, i.e. adjusts turbo boost. So logically engine should have enough air to burn off all that extra fuel.
As well there are about 7 settings (minimum to maximum boost), so you get the chance to play around and find your best.
Might be worth looking at.
I'm tempted myself to get one of these, but on the other hand also thinking to do a remap instead, once the warranty runs out. Not that I need all those extra 40 horses (20 will do just fine), just want to get rid of the "stupid pedal" syndrome on low revs.
Cheers!