if you want chrome looking ones pop down B&Q or somewhere like it get some screw caps. little dab of silicon and jobs a goodun
i got some black ones a while back (need to get some more thinking about it) but took me a while to track some down at a tool shop. they were perfect push fit so didnt need a dab of silicon.
i offten use the cmsnl site to get part info but have not actualy ordered from there although i have heard they are a little slow to post (around a week or so) but reasonable prices.