Asking about the best EBC pads is a bit like asking about the best sexually transmitted disease, IMHO.
I've used them on the kit car before and been deeply unimpressed. The softer ones are not very robust at all, even in a 650kg car, and the harder pads don't work from cold to an alarming degree IME. Plenty of others have come to the same conclusions.
I'm currently using Mintex 1144s but these would be too soft for an Omega driven even remotely enthusiastically. They are also not ECE 90 approved, so using them on a type approved road car would probably be illegal.
As always, the question to be asked is what about the current brakes are you trying to improve?
Different pad materials can change the feel of the brakes to a limited extent, and perhaps make them a little more robust at the expense of feel when cold for track use but that's about it, IME. For road use, I'd say you're best saving your cash and using standard factor pads. You have to try hard to overheat well maintained standard Omega brakes with road use.
Not sure drilled and grooved disks will make much more than a cosmetic difference etither, and you need to inspect them regularly for cracks.