http://www.aqua-marine.co.uk/acatalog/sitemap.html
try having a look at this place under hella lights guys. I know that hella have got car lights already but i don't know where you would get them from.
also be carefull as most LED lights probably won't meet uk law which specifies min/max wattage of lights not actual light power, ie LED lights maybe bright enough but may not pull enough power to meet the letter of the law. there's been the same problem on cycles for ages