[Budget] Around RM2.5k/AUD$800
[Purpose] Mainly gaming, internet surfing, and entertainment. Occasional graphics works and music recording.
[Hardwares that will be re-use]

I will be re-using most of my hardwares. Just looking for the best bang for buck upgrade path. Maybe a better graphics card and a new SSD. Is A GTX780 and a Samsung EVO a viable option for now? Or should I just wait, save and upgrade my entire rig in the future?

Intel Core i5 2500k (re-using)
Asus P8Z68-V Pro (re-using)
Kingston Hyper-X 2x4GB (re-using)
MSI GTX570 Twin Frozr III (upgrade?)
Corsair HX750 (re-using)
Samsung 1TB HDD (re-using)
OCZ Vertex 2 60GB (upgrade?)
Cooler Master CM690 Advance (re-using)
Liteon 24x DVDRW (re-using)
Cooler Master Hyper 212+ (re-using)

[Monitor resolution] 1920x1080
[Games & softwares that use frequently] Mostly FPS (current -BF4- and next gen.) and MMORPG's, will also consider playing some RPG's
[Personal preferences] nVidia
[Location] KL/Melbourne

Is the GTX770 good enough to play BF4 in all ultra settings @1080p? Is it worth the money to move a step up to a GTX780?

Ok cool. Thanks for clarifying.