What do I need noob

Hello all
I am a bang and Olufsen customer, I have just bought a Beolink gateway which is a network device that will interface my home av with this great lighting by Lutron

I am in the UK and need some help to work out what I need

In my kitchen I have 10x6watt LED's and would like a dimmer with some buttons that say entertaining, party cooking and maybe one other.

What decides do I need? Luckily in my kitchen I have both positive and negative in the wall box.
Are radio RA2 and the Grafic eye compatible?

What do I also need to connect the devices to the Ethernet network for cross network communication?

How deep do the back boxes need to be as I would like to use devices that are not too deep as my walls are solid brick and would need knocking into?

Sorry for all the questions.