Hi, dear shifus. Need your suggestions for building a gaming / simulations rig.

[Budget] RM3000 - RM3500

[Purpose] Mostly gaming / simulations

[Hardwares that will be re-use] None. Building a new one.

[Games & softwares that use frequently] Mostly, witcher3/Fallout 4/AutoCAD/ANSYS

[Personal preferences] Mostly will need to run some intensive simulations.. so please provide me bang for buck for the rig. Any decent 20" monitor will do.
Will require LAN card also for work purposes.
Preferably 6GB for my Graphics card.

[Location] JB area

Feel free to suggest me anything.