if buying the parts then sign up to eurocarparts as they regularly have 25 to 31% sales on and they sell Pagid discs and pads which I can recommend having just fitted them all round to one of my cars. Pretty much unbeatable with 31% off.
Other than that if you have a GSF near you then pop in and see if they will give you a 10% discount card or try buypartsby as they do mintex pads. Not sure what brand the discs are (possibly QH) but it is still safer than buying from ebay if no brands are shown.
edit: currently 25% off at eurocarparts if you use the code parts25
oh and if you have a branch near you then you can return anything wrong to the branch and they normally have dimensions and diagrams for you to check.