While I've never experienced an issue with the 30-year old OEM hoses on our bikes, this particular build is a more thorough restoration, so I made the choice to replace all four coolant hoses. As they're no longer available from Honda, I went with the only replacements that I'm aware of.
These beautifully-made hoses are manufactured in England by Samco (samcosport.com) and are available mostly through racing supply dealers around the world. Samco makes the claim that these are "the best hoses that money can buy."
The hose kit is $141 and the "German style" clamp kit an additional $30. The little red hose is a complimentary keychain — a nice touch, I suppose.
I purchased my kits through Samco's U.S. distributor, OPP Racing (.com). OPP orders from England, so shipping was about two weeks. The retail prices seem to be controlled, as everywhere I checked were the same.
The hoses install easily and the clamps seem to be of high quality without looking like Ace Hardware replacements. In this case I would have preferred no logo, but if you're going to spring for the best, may as well let everyone know it.
And Project 18's next owner will have just a bit more confidence in their new ride.