RE: MB339 - which one?
I spent 6 months looking and deciding the same thing and ended up buying the 1/5.5 scale C&C 2m one.
I wanted a practical scale jet that I could also compete with and the C&C one was the only one that ticked all the boxes. i.e. fly off grass, strong undercarriage, land slow, scale accurate with scale cockpit available and easy to transport.
The design is clever in that the fuselage splits just behind turbine so if needed you can easily remove the complete tail section with only four screws and two servo leads, rather than other models which are not practical to split due to having the join in front of the turbine.