Need more info on ur rig. What cpu you have.
intel core i5 3450
1. It means you cannot oc. Then u can go with H77 chipset. But if ur plan in future to upgrade ur CPU then u can choose z77 chipset mobo like Asus P8Z77-V LK. GIGABYTE Z77X d3h @ $130 around. These r best mobos at mid range for ivy bridge CPUs.
2. You will need maximum 500-600w PSU for ur rig.
U can go eh corsair, sesonic or xfx 550w PSU. It is enough for single gpu.
3. You can choose Gigabyte gtx 770 GPU @ $420. It is 1.11 GHz performance. So it will best suits to ur rig.
I hope it helps.