Where is the best place to get replacement panels for utes?

What panels are available?

Does anyone know of any places that have made other sections for you, and what did they charge for said parts? Doesn't have to be for a ute, sedan, or even a datto, just trying to find out some prices on custom repair sections. There's a hot rod resto place in Tiaro QLD which makes custom repair sections but they charge a fair bit.

My ute already has a new tailgate and front apron. I just need some bottom corners made up for the windscreen hole (a patch which replaces an area within a 75-100mm radius of the corners of the windscreen)

The sills need replacing, from the back of the cab to the front of the rear wheelarches. I need to cut off and replace the drip rails and repair the a-pillar and roof where they were attached. The rear seat supports have been removed completely and the front seat supports have been butchered to fit racing seats (previous owner's doing, I'm going to be fitting standard 1200 wagon seats without headrests).

I also need to cut out the floor of the tray and buy a sheet of 1.2mm and get some ribs rolled into it similar to what they have from the factory. I need to somehow replace or repair/straighten the chassis rails/subframes which extend back from the firewall under the front floor pans. The front floor pans are ok, they just need a bit of patching up, but i might have to just fork out for new ones because they will need to come out to repair the rails/frames underneath. Does anyone have any suggestions on how to support/reinforce the body properly so that when the floors and such are removed and the new sections are welded back in, the body isn't all sagged/twisted?