7770's in crossfire setup aren't a good idea. One strong card would be better. Like a 7850/70. If you can still return them, I recommend doing it.
As for the CPU, overclock it and it should be running fine.
Again, pretty sure that the issues you might have aren't CPU related, but because you paired 7770's. Which shouldn't be bottleneck'ed by a 965, even at stock speed.
Your first question should have been "Will crossfire 7770s be good?" to which the answer would have been what he said
As a rule of thumb don't get two weaker GPUs over one strong one. Ever. Of course there are exceptions but it's a good rule.