500W is fine, I'd say you're good for your specs. You might want to look at another motherboard (unless there are specific features found only on that board) since the Z77 chipset provides no real advantage over the H77 chipset if not overclocking perhaps something like this http://pcpartpicker.com/part/gigabyte-motherboard-gah77ds3h
You should be good with that PSU. There isn't a lot that you are drawing with that system, and unless you are going to start OCing heavily, you should be fine.
Ok, great, thanks for the answers! C12Friedman, unfortunately, I am stuck with the Gigabyte GA-Z77X-UP4. It's a great board, so I read, but a bit expensive. I have an Apple Cinema Display so I need the thunderbolt port(s) on there.