Hi I have a MSI Z77A-G43 mobo. My GT 8800 has just died (it has lasted very well) I need some advice on what GPU to buy now. Should I spend money on just one good GPU, or crossfire two ok ones? I have an intel i7 chip. 750 watt power. 16 gig ram. Also, is it ok to run Radon GPU with a intel chip?