Speaker Cables and Connectors

I have no experience with Focal's, but I think it would help if you described the rest of your system.
A lot depends upon that information as to what will work for you.
B

My recommendation is to forget everything irrelevant like your other components and focus on the one thing that matters, how they sound. Really. I cannot think of anything less relevant than... all the other stuff people will mention. Anything other than how it sounds, forget about it. That's my recommendation.

I would follow Focal advice: a cable 4mm or larger depending on length and some good banana plugs from parts express, or kabeldirekt for example.

What is your budget? Are you a DIY sort?