Try gardens4you.co.uk

Kordes is just the name of the breeders - you need to find the name of any of their roses that you want, and then look for that name rather than Kordes, for instance, I've got Korresia, which is a Kordes rose, and if you google Korresia rose, you'll find it at David Austin.

Kordes does have their own site, where you can look at what roses are available, but you'd probably need then to look for them in the UK, see here

http://www.kordes-rosen.com/kordes-fragrant-garden