Updated for HG'22 I get something like this:
100 Dt, J-2, M-2, MCr 20. Can operate at J-1, M-1 with up to 100 Dt external load.
One Stateroom, 70 Dt cargo, two modules of 1 Dt each.
Possible modules include better sensors, repair drones, docking clamps, jump nets, fuel processor, escape capsules, etc.
The cargo hold can be fitted with demountable fuel tanks (20 Dt standard), crew pods, passenger pods, labs pods, workshop pods, etc. A collapsible tank allows cargo space to be used to extend range as needed.

No turret installed, but a hardpoint is prepared with the fuel processor in its space. It's simple to replace the fuel processor with a turret.
The ship is prepared to operate with up to 100 Dt external load: External tanks, external cargo, and/or pods or small craft in clamps.
The ship is prepared for automation with e.g. Virtual Crew, Expert software, and/or Repair drones as optional extras. The computer is slightly oversized to be able to run e.g. J-2 and Virtual Crew-1 at the same time.
The ship can be very profitable in a basic configuration:
Standard 10 Dt pods can be lined up like train cars in the hold. Custom pods can be made to order. Note these are not a modular hull, they cannot be replaced individually, and require a starport to rearrange (like demountable tanks). The pods have no access to the outside of the hull. Pods are assumed to have a central corridor to allow passage to all parts of the ship.
Standard Accommodation Pods:
10 Dt, two staterooms, 2 Dt common area, MCr 1.1.
10 Dt, four small cabins, common fresher [two staterooms], 2 Dt common area, MCr 1.1.
10 Dt, large room, bunk beds, common fresher [10 barracks], MCr 0.5.
10 Dt, luxury suite [luxury stateroom], MCr 1.4.
20 Dt, luxury stateroom, stateroom, library, 1 Dt garden, 1 Dt common area, MCr 5.7.
A variety of lab, medical bay, workshop, and stable pods are available.
Pods are generally arranged with accommodation in front, fuel in the middle, and free cargo space in the rear.