I've seen and heard a fair few people comment that the EBC stuff isn't that good, particularly the greenstuffs. If it's for the rear, I would (and have) gone for bog standard replacement pad as they don't do an awful lot of braking anyway. Have you got uprated pads on the front at all? If not, then I definitely wouldn't go for an uprated pad on the back.
On the discs, I couldn't really say - I just use the OEM equivalent discs from my local branch of partco and they do the job just fine.
If you skip past the bit on different calipers in this thread there's some useful information there.
Jon.