You also need to save your money for another parts of your car, if you can afford:
1) full exhaust (I am using 2.5" all the way, midbox +S-flow, more than rm1K)
2) oil cooler (engine oil and transmisson since mine is auto, another rm1K for both)
3) brake upgrade (I am using steel braid hoses, better pad, around rm700 for front and rear)
4) suspension (I am using IMProve abs, around Rm1K)
5) lower down your compression (either metal gasket or change forged pistons, i am using metal gasket)
6) some gauges to monitor your car condition such as boost, water temp, oil temp and pressure etc.
7) better tyres
still many more to be list out. Yes maybe you think it is not worth to put so much money on a proton car but its all about how you enjoy the ride sometimes, anyway, I'm okay with it.