Finally, after surveyed and get quotation for more than 6 contractors,
I deicided to use this contractor which recommended by forumer pm here.
He is the cheapest among my survey.

This friendly contractor name is Mr Koh,  Company is Winner Steel from klang, 019-3264809
I got mr koh contact at 10am, text him at 11am, and he managed to come all the way from klang to cheras in 2 hrs.
heavy rainning somemore, so efficient and good attitube.

The most crucial points are good workmanship + Reasonable price + Superb service.

let pictures tell a thousand words

Material used : 3mm Solid Polycarbonate (Grey)
Size: 18 X 7 ft (132 sf)
Price: RM17 /psf
Timeline: 5 days
Steel Coat : Leather brown (FOC)
Installation : FOC
Pillar : No pillar design (look neat)
GST : N/A
Conclusion:
Very satisfied and two thumbs up !
Good workmanship + Reasonable price at today market.

Hope other forumers find this review useful