Hi Cyanic, I can help - I have plenty of experience in UK web promotion. I suggest you pay for inclusion in the following SE's and directories:
FAST (http://www.positiontech.com/fast/index.htm)
Looksmart UK (www.looksmart.co.uk)
Inktomi (http://www.positiontech.com/inktomi/index.htm)
ASK UK (http://askjeeves.positiontech.com/)
AltaVista UK (www.altavista.co.uk)
Yahoo UK (http://uk.yahoo.com)
You could also opt for the Overture UK and espotting.com PPC models.
Yahoo is pretty expensive and may not result in a positive ROI, however I strongly recommend that if you have the budget you should opt for the paid inclsuion even if its just for the purpose of a 'heavy weight' link to get you into google uk.
Hope that helps, please feel free to email me should you need anymore advice.
Cheers, Lee.