I have used this mob for a couple of screens previously. Always done good work and have been very well priced:

www.handcraftfibreglass.com.au

2/19 Prince William Drive
Seven Hills NSW 2147
M-F 7am-4.30pm / Sat 7-11am( subject to change eg public holiday weekends etc)
Phone. (02) 9674 3586

Chopa, there is a mob at Moorebank off Newbridge Rd called Lingel
2/ 26 Kelso Crs Moorebank NSW 2170
9824 0689

+1 for Eagle Screens

Have used them more than once

I had a blank made by A.J. Plastics in Breakfast Creek Brissy. Has templates for most screen shapes .mine was made of a Mitsubishi acrylic.