Moto Rapido have their own made, exactly like the renthal one, billet alloy with the flange, but really nicely anodised, craig sent my make a photo of one, and about £15 cheaper thant the rental one. i think they do the DSC discount too, not sure.
call craig, im sure he can send you a photo.
dont know his email but you could try wilf? he's on here somewhere.