I always liked the panel truck versions best--especially the 1960-66 ones,with barn doors and the arrow shaped tail lights...(I remember seeing a nice '66 or so panel suburban used as an ambulance,on the show "Emergency" and Adam-12,that was red and white,that was one of my favorites!--in one episode it got T-boned though!

)...
the 55-59 ones are pretty cool looking too..I had a 1971 K1500 Suburban but it was the usual 3 door with windows,I never registered it as it was too rotted,so I used it for parts for my 71 and 72 K5--the engine ended up going in my 2wd 75 K5,a lowly 307,but coupled to a Vega saginaw 4 speed,it scooted right along pretty darn good!..
I have seen a 73-87 style Suburban at local cruise nights that someone sheet metaled over the rear windows,leaving only the ones on the front doors and rear barn doors intact,I wish GM had made panel versions of them factory,it looked very cool...I've seen a K5 around a '85 at the cruise nights that someone put Suburban barn doors on it,and "paneled" the rear glass over with metal-- that looked pretty neat too..
if the windows on the back of my Burb ever got busted I'd probably make a panel out of it,I'm sure the factory privacy glass is neither plentiful or cheap in junkyards!..