I have decided to stick with the Jet A1 gears, they look anyhow terrific.
Had a friend make alu tubes and used longer 6mm piano wire to lenghten the legs. Thereby I shortened the nosegear a bit to get a lower angle of attack after landing, so hopefully it will glue itself better to the ground.
In all it looks very sturdy now, the Behotec gear mechanism just slipped in the old Eurokit mountings, only I bought a UP valve because it is now an Air/Air system, unlike the spring/air of Eurokit.

The longer legs fit exactly in the recesses, only the area around the leg itself had to be opened a bit more, and I have to make wider cover plates that will be attached to the gear legs.