For £150 you'll not be getting a genuine part so may as well get that copy. There are loads of copies about, some on ebay and a few on the net, all for that price. Try to get one with a seperate diffuser and with a heatshield.
I'm sure Nige at BCS would also recommend getting a proper OEM part for fitment with his big arse tail pipes.
My geniune R32 rear end (below) with BCS 100mm 35 degree slash cut tips, there isn't a lot of spare room so bare that in mind. If your still getting a copy then get the smaller 80mm tips to be safe.