You can purchase right-angled SATA connectors, have you tried looking into getting one of those? It would be much cheaper than a RAID card.http://www.newegg.ca/Product/Product.aspx?Item=N82E16812200050
Edit: At 3$ and SATA 3 cable you can't go wrong.
Edit 2: For some reason I can't visualize your GPU covering your SATA ports. Does it literally cover the sata port, or would there be enough room for a right angled SATA cable?