I don't see any place where the OP listed his selected PSU was 80+ gold. I don't even see a mention of brand or where he's ordering from. According to this handy dandy
PSU calc, his rig will pull 325W without OC. The only reason I suggested he upgrade his PSU is because there's no guarantee what brand he gets, and it wasn't mentioned. If he was rocking a legit PSU model, then 400-550W is sufficient for his purposes.
The onboard WIFI for the P8Z77-V is weak, about 1 bar weaker than a USB dongle. If you're going to rely on WIFI, you're going to want a more powerful adapter (especially if its for gaming). If you're only looking for the onboard WIFI in the P8Z77-V, the $50 price premium is not worth it. For the OP, it seems like his price premium would be more along the lines of $100-150.