Powercolor R9 280 Turboduo, $285. Can play your games at max settings in 1080p. Your PSU should be good enough to power the R9 280.
A R9 280x should be more than sufficient. Or top up to 455 for Sapphire Tri-X R9 290x promo now. Overkill for the games you play but you have options for playing more games at higher settings in future.
Sapphire R9-290X 4GB Tri-X OC going for just $405 after discount on Lazada appdo i need to change psu for this?