On the standard 312mm disc with cheapish pads I've tried: ATE / Mintex / Bosch / EBC / Ferrodo / Pagid - I find them pretty much the same, except for cost.
The performance starts when you go for the likes of the Ferrodo DS2500 / Mintex 1144s / Pagid Blue etc.
So, unless you're going to spend over £100 I wouldn't bother and keep with the Standard pads or OE replacement, and get a fluid change.
The R32/S3 calipers offer much more power than the standard setup, but very heavy.
I'm not sure why the 4 pot brembos were not moved on from the 1.8T Cupra... probably cost.