Not sure exactly where exactly is classed as the North West, I'm from down south and pretty much the whole of the UK is North West of where I am.
I was really pleased with the metallic lime green powder coat job I had done at LSN Coatings, Castleford, West Yorkshire: http://www.lsn-coatings.co.uk/
, Cost £40.00 for frame and forks and it was done in a week.
I don't know whether they do RAL 1026 specifically, but if you look at the gallery page they do a fluorescent yellow and orange. Might be worth giving them a call.