TJM Alloy full length works for us. Carries a roof top tent, awning etc with ease. I did trim the rear 3/4 of the rails to make it flat, so the eezi-awn would sit right. Picked it up on flea-bay for $400.
Currently using ARB full length rack steel on the GU , but just bought a Rhino Ally rack off the inlaws used twice to keep the weight down on the GQ that i am fitting out cheers & good luck with the mods .
Ocam full length aluminium tradesman style rack. It's relatively aerodynamic and light, yet still strong enough to mount a 28kg awning and stand on. It has rails on the side to secure cargo, and a plate section at the rear which is ideal for me as it provides a whether shield above the rear doors that overlaps the back of my wing awning and stops rain from getting in when the rear doors are open.
I have a full length steel tradesman rack that I bought second hand and if I was buying a new one today it would be an Ocam full length aluminium tradesman style rack. At $600 they are a great price for a full size, well made aluminium rack. The Ocam has more width between the side rails than most similar racks but still not quite enough for a full size sheet of ply.