in this case you need to google, there are lot of sites that offer e107 themes.
you might find this interesting once you have found a theme and find out that it is fluid / fixed width, which is not suitable for you.
viewtopic.php?f=50&t=800this explains how to change theme from fluid to fixed (and obviously you can reverse the progress to make it from fixed to fluid).
before i had lot of problems, cuz i couldnt find a theme i liked in fixed width.