If you want OEM then the rns510 is the one to go for. Prices they range from £400 - £700+. If you want streaming music you need an mdi, as said above or bluetooth. I think they are upto J or Hs or higher, best one to go for is the one with led screen which started at C. Eddie off here can get them, nick off r32oc can or ebay.
I wouldnt buy the copies, save a little more and get the real thing