An 8ft bed Ford truck is available in a regular cab and a Super Cab. The Super Crew is not available in an 8ft bed because the market share was so infinitesimally small that the decision was made to halt production.
Nobody makes a 4ft full-size truck, so I'm not sure where you get that from. The 5.5' and 6.5' bed trucks with a crew cab is what the market demands. The manufacturers will not make a vehicle to satisfy 2% of the market. I shake my head when someone scoffs at the soccer mom driving a truck around. Who cares. They purchased that vehicle because it fits their needs, not because it did or did not fit someone's perceived notion of what a truck should look like or be used for.