Yup. The best I've come across is www.willsmarine.co.uk
Best to ring 01548 852424. Mark Chapman is the guy who knows all about everything and they stock thousands of spares which arrive (Devon to the Lakes) next day as a rule.
I know LS has had good service from Willsmarine but I also have a note of outboards-direct.co.uk (I think thats Oakley Marine in Brighton) and outboardservices.co.uk in Falmouth
BTW you might find the Engine parts diagrams useful. They will enable you to ID the parts you need