Will this be a good gaming PC?

Pointlessly overpriced motherboard, anything with 'Z87' written on the box will do the exact same thing and will save you $100. PSU is also pretty overkill both in price and wattage, anything from Corsair/Antec/Seasonic/Silverstone etc in the $60 range will work fine, Corsair CX600 would do it.

Use the cash saved to buy a proper keyboard and monitor. Also might want to do a bit more research before dropping $100 on a headset; headphones that advertise surround sound are a waste, you only have two ears.