I like the Regina hollow-pin chain a lot and have them on a couple of my bikes. They seem to last a while, though I do keep a fairly clean drivetrain. However, for your LOOK, you'll obviously need a narrower modern chain. The new Campagnolo 12-speed chains have hollow pins and weigh a mere 228g. That will save you about 35g over your C9 chain (263g). Something like a YBN titanium chain is nearly triple the cost at ~$200 and only a slight weight improvement at 220g. Any reason you couldn't use a 12-speed chain with your 9-speed LOOK?
Colorado Cyclist has them on sale:
https://www.coloradocyclist.com/camp...12-speed-chain ($1.57 plus tax & shipping per gram saved!)
I've had fanciful notions of adding a super-light titanium freewheel on some of my lightweight builds, but they're always super expensive and nearly unobtanium in the wide-range options my fitness requires.