You will be much better off with the 4pot brembo conversion tbh. They fit on 16v hubs and you only need 2 washers to space them correctly
Alot better performance then 172 calipers aswell.
You will need:
Pug 406 Coupe V6 Brembo Calipers (About £200 but can be had for alot cheaper if you look properly, PM me ;) )
Clio Rs (172/182) Standard sized front discs (Not sure but not expensive)
2x 3mm thick washers. (couple of pennies
)
1 set fo widetrack frotn brake hoses (williams/19 16v) (Again not sure but not massive amounts)
Oh and this conversion will fit under CERTAIN 15" wheels including willy wheels.
Patrick