I need a team that does the full cycle of development but I have to stress that the designers from this team should be creative and professional. Any suggestions?

Yes. The design is a weak spot for many teams of developers. It is just the state of design in general I think. But there are exceptions and I can recommend a team of developers that does very creative designs. Here, check this snapchat UX case study . It will show you how they approach their work in general. And you can find other examples of their work on this website as well. So click the link and see for yourself.