Wemoto do a search by model for most bikes.
For brake parts in the past I have used the EBC catalogue online, there is section that let's you see other bikes which use the same pads. Sometimes you can find that one manufacturer will have the same pads cheaper than others. Also I needed the little slider plate/clip that sits on the rear caliper mount, Suzuki do not list this as an individual part, it's only available with the whole caliper mount for over £100. Honda CBR600 uses the same pads and they have the plate/clip as an individual part for about £6 .