Ok, now i know what mirepup means. It may depend on my bad english ........ so.... sometimes i'm a little bit slow
What he said was my first idea, set them as featured when they become premium member and redo it when they left the membership. But i had no idea how to do so ! So my next idea was, to have at one site the featured function where i can set profiles manually and at the other site a real membership where its profiles will be shown in featured box on index page.
Thats what i did and it seems to work perfect until now
Thanks for your help Prometheus and mirepup !