I'd go i5-3470 and HD7870XT, or consider going AMD. In Crysis 3, the FX6300 beat the i5-2500K, and the FX8350 beat the i5-3570K, and in some situations the i7-3770K. The FX-8350 is around £30 cheaper, and the FX8320(Easily OC'able to FX8350 speeds, even on stock cooler) is around £60 cheaper. Crysis 3 isn't an exception either, with modern drivers and hotfixes, the FX8350 often trades blows with the 3570K and 3770K, while costing considerably less. The biggest delta is probably seen in ArmA2/DayZ, where the FX8350 does a noticeable amount better.