Patch Panels

['72 Chevy Suburban]

I pretty much need to replace the lower part of my '72 Suburban as the rust-belt environment has taken it's toll on the truck. Are there any better panels than others as far as quality or fit? Are there any lower patch panels that are unavailable for the Suburbans, and which parts should I buy to modify for these areas?

Does anyone make a patch panel for repairing the window channel on the inside of a clamshell tailgate?

Thanks in advance,