These (sub)compact pickups are 4.50 m long, and can carry 700 kg.
Mid-size pickup trucks are 5.20 m long, and can carry 1000 kg.
The latter are much more expensive, of course.
In 2015, the Renault Duster Oroch was launched. It's 4.70 m long with double cab, but can carry only 650 kg.
In 2016, the Fiat Toro was launched. It's 4.90 m long, but can carry 1000 kg. And it's much cheaper than mid-size trucks.