I'm looking for a spare set and there near impossible to get second hand. You can still get them from rieger but the arches are £800 inc vat or £215 each from online autosport.Then the skirts are £150 and bumper's £250 each. nk tuning were doing copy's but they have stopped production of the now.
Then there's fitting your looking at £3000 as all the arches have to be rounded, the fibreglass arches have to be trimmed to fit the contour of the body as they dont fit out the box.
Then there's wheels, in order to fill the arches you will need big wheels, im running azev c's 17x10 and 17x8.5 et15 and tyres 245/35/17 rear 215/35/17.Mines only recently been done, there's pictures on mig web