I'm always amused when an old thread resurfaces. This one was dormant for 5-1/2 years.
In those years I've bought and parted out two 1/2-ton panels mostly to collect parts I need for my Suburban, and a 1-ton panel because I've had two crazy ideas, one to use the rear sheet metal to form a smooth sided bed for a 1-ton truck and the other to graft that long panel body to a COE cowl to create a custom COE.
But the real question posed was 'why did you chose a panel or suburban over everything else?'
My answer is that I didn't. Today I have the two Suburbans and the 1-ton panel. I also have two GMC 1-ton trucks, two COEs, two big bolt Chevys and a big bolt GMC. Plus two 1/2 ton Chevys and enough parts to make another.
My GMC Suburban is a 'Z' series which has an open driveline and is titled as a '55 so I call it a '55 1st. It has the curved glass windshield, the distinctly GMC dash and the chrome grill with mustaches.
I've found that its that Z-series GMC look that I like best and while I'm not sure why, its very likely the next truck I buy will be another of those. I have enough sheet metal parts to build the COE Suburban Cargo project I've described I've decided I want to base it on Z-series parts so I'm keeping my eyes open for both a Z-series COE and 1-ton panel.
I told the story early in this post of how I ended up with my Suburban, but today my answer is really that I want everything Z-series....