That's a good question. I'm a believer in SCROG, but I haven't done one myself. This is only my second grow since returning to the hobby and prior to that was gorilla growing in the woods back in the '70's.
I had limited space on my last grow, but I just went with a 3x3 tent so I plan on filling her up with a gotilla glue and a gold leaf!
This fall I will be be adding a second 3x3 tent so I'm working my way back up.
There are lots you can use for a scrog. Some guys use mesh, other guys make them out of string and basically string their own. Otherwise you can use fencing too. My local hardware store sells this plastic coated mesh fencing that would make a perfect scrog net!