I'm in the same position as you OP and got the same question really, whether to go oem or whether there's a decent upgrade for the same sort of money. Had a look on eBay though and you can get brembo discs and pads for £330 or MTEC discs and brembo pads for £300?
http://www.ebay.co.uk/itm/401196414212
http://www.ebay.co.uk/itm/331877984781
http://www.ebay.co.uk/itm/330606505596