Dealers quoted me R460 for a set for the R53. I would pay that twice in stead of using normal ones because anything above 110 and normal blades start lifting up.
That said you can buy normal bosch ones and just replace the rubber part, to retain the wing on the driver side blade.
But do this. Go to Midas or Autozone or Nascar, eve your local fuel staion. Buy the correct length wiper blade, strip out the rubber of the old bmw blades and put the rubber from the new ones n.