Thank you for both of your answers. I think the Custom Page Templates are exactly what i was searching for. I think this would be the best and i had full control over them. I used them before but in my curent problem i didnt thought about this possible solution. Thank you very much for this idea/hint 😉
No, it’s not a generic custom page template. front-page.php is a new Template File in WordPress 3.0+.
I am sure that the wordpress developers think something with these two template files. But what? Thats the question.