I fitted mine last weekend, have done 100 miles now, and are already working much better than the standard.
They were off of a 306 hdi estate, but there are a few others you can get them from (306 2litre xsi for example).
Mine were lucas calipers, so the carriers needed a small piece grinding off on both ends, very easy to do and there is an example of where you need to cut on another post.
Other than they they bolt straight on to a saxo with the 266mm discs that come on these 306's.
These will also fit under the 14" VTR wheels too.
I would strongly recommend that you get some braided hoses too, as these make the pedal a lot firmer under braking.
It is one of the best modifications i have done to the car!
Jimbo