Focal Grande Utopia...You've got a set of serious speakers there. I've never heard a setup with them sound bad.
Just try as many of top-of-line models brands as you can. With that level of speaker, a proper dealer will have demo cables for you to try in your setup. You're gonna drop some serious dough, so a real dealer will be ready to help.
Pure subjective call for your ears only.
Any decent cable/brand won't prevent your speakers from sounding great. I'd just get Nordost Odin and call it a day to enjoy the setup.
Impressive looking/sounding speakers should have cool looking cables to match.