That power supply will power your system just fine.
I don't imagine your quad will bottleneck your system. Also, I'm unfamiliar with your motherboard. On newegg like you said, it says pci express 2.0 x16, are you sure this isn't the case? Regardless it will be backwards compatible with pci express x16, however, I'm not certain as to whether or not that will cause a bottleneck.
You may come across some games that will leave the gpu bottle necked by the cpu(the game will max the cpu before being able to max the video card, just crank the graphics higher and if the performance stays the same, you have maxed the cpu), but it should not be an issue for the most part. This part is very game dependent.