Hey TIG,
the second is what i thought would be good first but i couldn't manage to get the object manifold in the result so i wasn't able to print that. I've tried curviloft for that and it worked great. I think my object was the problem.
In the end i tried to simplify it and drawed something like in your first picture this morning which seems to work well.
I'll post an image of the printed part later on but anyway thanks for all your great tips.
@TIG you didn't arrange this pictures just for me, did you?