I've seen no information regarding career as a trucker in Malaysia, mostly I've seen are overseas

IIRC they pay handsomely with the drawback is not having much life outside of your trucks

I've been thinking about taking Lesen E Full then onto GDL E Trailer, cost somewhere around RM3k/RM4K for both of them licences

What pique my interest is being an oil tanker driver as I have previous experiences with product discharge checklist of a tanker into the station during my fuel pump attendant job at Shell

Need advices and thanks in advance

Are you a smoker? If you are, find another transport job.

Transporting bulk liquid has its own set of challenges different from general cargo.
You think you have what it takes to be DG Class 3 Driver? Aware of the occupational hazard and the risk? Personally, I'd rather not.
These companies have very strict policies and demand high discipline and rule adherence. They usually recruit drivers with some experience but if you think you have what it takes to be one, no harm in contacting them.

For starters, here's one.
https://shazimantransport.com/
https://shazimantransport.com/career/

Good luck!

I give u tip , trucker under alot county gms list mean that u can easily get PR oversea . Get 3-4 year exp then go overseas yr salary instantly jump 10-15X .

Go for it. Get exp, either be boss here or go work oversea if you prefer to be employee.

No life but good money.

Oil tanker drive would be highest paid with regulated driving + training.