7870XT is best bang for buck, a card with best performance price ratio..offer same performance with 660Ti with less (alot) money.
Of course, if you have plenty money to spend, 7950 is the best choice..but there are just small performance gap between 7870XT and 7950..
Well, if i were you, i'll take 7870XT and the board with FX990 chipset..
With FX990, you'll have better overclocking and higher crossfire performance, more stable, and at least your board ready for next steamroller processor..
970? meh..