I noticed on the CPU support list it says it doesn't support my CPU until BIOS Revision 1.4.
What if the one I have has a earlier BIOS?
Don't worry about it, because you can see the BIOS 1.4 that came out 5/16/2012 so that you just fine to use the i5-3470. And other note is that do you want to updrage the cpu later or not?
Because you can't OC the CPU, why not get the other morthboard like the B75 and you can save some money to buy the good GPU. TheB75 is the sister of the Z77, but B75 can't OC the CPU.
Here is some info for the B75, keep in mind the B75 is very limited overclocking/voltage options but it is low cost and high-level of performance.http://www.techpowerup.com/reviews/Gigabyte/B75M-D3H/http://uk.hardware.info/products/1773/7982-intel-b75-motherboards
I just recommend this and you are fine to get the Z77.