Like all spares from Honda, there will be better aftermarket options, as well as worse ones... all you can say about Honda parts is that they will be of an adequate standard. In any case, I doubt that Honda actually make the chains so it makes sense to seek out good quality alternatives. Febi Bilstein have a good reputation... I've been looking at replacement options and I believe these are the right ones:
http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=febi+30699&sprefix=honda+timing+chain%2Caps%2C241&rh=i%3Aaps%2Ck%3Afebi+30699
http://www.amazon.co.uk/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=febi+31115&sprefix=honda+timing+chain%2Caps%2C241&rh=i%3Aaps%2Ck%3Afebi+31115
A little more expensive, but these are definitely are the right ones:
http://www.bestpartstore.co.uk/honda-accord/accord-viii-tourer-cm/17486/10511
I understand that the kits from Honda are around £500?