I am not sure wether to get a R9 290 at 4GB for £200 or 2 GTX 650 at 2GB each for total of £180. I think the Nvidia option is better but, 4 months down the line I would buy another R9 for crossfire, would it be better to save money and go with the GTX 650? I plan on OC, any input would be much appreciated thank you