Choosing a new graphics card/ motherboard

Hello everybody, as stated in a previous thread of myn my graphics card has finally gave out on me, I had an ATI 5970 and it lasted me about a year, unfortunately when I called the manufacturer I was outside of my warranty and so I just have to buy a new card.

Its been awhile since I have gone shopping for a new graphics card and such so what is catching my eye right now is the Ati 7970, the only problem is that it uses pcie 3.0 while my motherboard only has pcie 2.0 slots (I have a Gigabyte GA-EX58-UD3R)

So heres the questions that I have:

1. I know that you can use a pcie 3.0 card in a 2.0 slot and it wont get as great performance as it would in a 3.0 slot, but do you think I can still get just as good or better performance than my 5970?

2. If I decide to get another motherboard is there anything out there with a LGA 1366 cpu slot and pcie 3.0 (I tried looking but couldnt find anything)?

3. If its just better for me to stick with a pcie 2.0 card than what can I get that will compete or perform better than what my 5970 did?