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You can put your custom menu (horizontal) in the theme.html of whatever theme you find that has a look that is easily customized by you. I have created many types of horizontal menus, though none as pretty as yours. 7dana.com, 4thefort.com, petitoops.net and many other sites have free downloads of themes. Some of these sites, you have to register at, some not. You should look through different themes and see how easy they would be to customize. I believe the Colors theme is easy to change, and the imago themes are easy too.