In Crossfire 5770 is almost equal with the old 5870 http://www.guru3d.com/article/radeon-hd-5770-review-test/15
.Now is your decision. If like to play games sell the 5770 and buy a 6850 , 6870 video card ( i recommended this because are good budget video cards)
If work with your PC ( video rendering ,3D design and some other heavy programs) the i7 2600k is a good investment.
If you aford buy a bigger SSD 120-128GB for OS and other programs what you use mostly and need a quick boot.If not a 64GB for OS is a good investment.