At 720p, might be worth looking at something like a GTX 750ti or a R7 265. They should be able to run most new games at very high settings at 720p since I run my GTX 750ti at high for most games at 1080p and get around 50-60FPS. If you plan on going 1080p in the future, a GTX 950/960 might be worth it but they are generally about $100AUD more than a GTX 750ti and its not worth the price at 720p