They are owned by ECP (so basically the same company) and their prices are the same as ECP ones with the discount. I think ECP massage their prices to make it look like you are getting a good deal with the codes....
From ECP or the site I posted? Just watch the quantities if you order discs as well - pads are priced for the set (per axle) whereas discs are priced singly...
From the site you posted - same as Eurocarparts like you said. Not doing discs right now - the fronts are fine I think as they were new 16k miles ago, the rears I'll have a look at when I get the wheels off.