How could I make Twitter headers for these?

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I have 5 profiles with good looking logos and I need to make the headers for this. It would need to look very good overall, I guess something like complementing whats already there. Can you suggest me what could work with this? Some online tool, or some simple design in Gimp… Like maybe base the colors of the header on each logo, or something like this (or like a color palette). I am not a graphic designer at all, so basically I would need to get some info that would enable me to get this done (acceptable or good result, the beter the better, obviously).

Thanks in advance for any help.

Screenshot of the profiles:
http://prntscr.com/lb3dx3