An option for bucket seats
 

I was looking at a 1990 Suburban the other day and it had bucket seats and instead of a center console it had what was called a "buddy seat" (or something like that) in the late 60's and early 70's trucks.
The buddy seat folded down and had two cup holders made out of wood and arm rests on the back of it. There was no console, just a seat back.
So I was looking underneath the seats to see how it was mounted and the buckets and the buddy seat were all mounted to a frame that was mounted to the stock floor mounts. I am pretty sure the truck benches and Suburban benches mount the same way so this looked like a good way to mount buckets in a truck.
If they mount different then please disregard everything I have just said (or typed).

Re: An option for bucket seats
 

The aftermarket buckets I have seen are mounted this way. They used, essentially, a rectangular frame made of steel with tabs for the 4 bench seat bolt holes. The buckets just bolted to the steel frame. I have been keeping an eye out for one of the frames when I go to the local junkyards since they look like a good way to mount a set of junkyard bucket seats into a pickup.

It sounds like what you saw was a set of aftermarket seats. The factory pickup buckets mount to the floor at four points for each seat.

I think, but I am not sure, that the floor is different in a Suburban because the gas tank(s) are under the floor of the pickup, but not in the Suburban. If that is the case, the ones you saw would not fit a pickup.

Slonaker