SkipStone is currently under heavy development, but its progressing quickly and coming along nicely. It provides a nice and simple configurable interface, bookmarks and all of the other mandantory browsing features.
Downloading is handled by SkipDownload by default, a Gtk+ frontend to the famous web downloading utility wget. However, if you prefer to use other download utilities / managers, this option is configurable.
Mail and external url handlers are also handled by external applications which can be configured to the users choice, leaving SkipStone to do what it does best - browsing.