Tooth spatula / tile adhesive: What do you recommend?

Hey,
We will start tiling soon. Porcelain stoneware 30x60cm on underfloor heating.
Which notched trowel 8mm, 10mm and which tile adhesive would you recommend?
We were thinking of Flex adhesive from Knauf. Is that okay?

Best regards
Bollermann

I used 10mm putty for the measurements. Adhesive from PCI, the Nanolight. It is very easy to work with.