Most of the well known on line sites are pretty reliable. When ordering I find it's usually best to phone to check availability as some sites don't get updated that quickly when stock is sold. Places I've used with no problems = srsmicrosystems.co.uk [next day service and very helpful - but not sure if they actually stock Canon!]. parkcameras.co.uk - another site recommended over the years by lots of DCMag site users. cameraworld.co.uk - I've used a few times - changed faulty goods with no quibble . Always worth checking out the bargain basement on warehouse express I saved £200 on a D300 with full warranty and a very cheap mint condition Sigma 70-200 that way. For second hand/refurb you could try the canon outlet on ebay. Also on ebay Kerso is highly recommended
http://myworld.ebay.co.uk/kerso&ssPa...MEFSX:SELLERID
Would'nt recommend camerabox.