Description
The Fiddle Squid Two will take 20 Kerbals to orbit, and still have 4800DV to get to destination and back. This range should allow you to get from the runway, to a station orbiting Duna, then back to the runway without having to take on extra fuel.
Revision A
I removed the small heat panels, and two of the antennas. I also moved the wing and landing gear back just a little. This makes the plane a little more sluggish when fully loaded, but makes atmospheric entry much more stable.
Built in the SPH in KSP version 1.3.1.