Sorry to be a pain with a fairly simple question but Google wasn't too clear. What size tubing is best for bleeding the brakes on a 2003 s60 D5?

There were conflicting reports of varying sizes front to rear, but if there is a tried and tested size that gives a snug fit on the nipples I'd be most appreciative.

Also, before I read the haynes book of lies, is there a preferred order in bleeding the calipers? I assume, to work from the farthest caliper to closest to the reservoir?

Kind regards,