What to use to mount panels

gtxkid

I am in Pensacola FL.
Need to know what to use to mount some panels on the roof.
Roof is almost flat.
It has a rubber membrane on top.
From inside the attic i have a lot of room and can see plywood from underneath.

The UNIRAC i have some of is: http://www.unirac.com/?q=commercial/commercial-products/u-la-commercial
It is more for ground mount but would like to use it on the roof.

Need to know how to go into attic and support the roof and what to use for mounting.

Gets hot down here so spacing them up from roof some is a plus, and also using Micro inverters under them.8)

All suggestions welcome