Moray is one of the best 3D modellers out there for povray. While many 3D modellers/renderers support the ability to export to povray format, Moray has been designed all along to be used with POV-Ray (though it does support Polyray as well). A shareware version of Moray can be downloaded, but a nag screen is displayed after using the program for long periods of time. Unfortunately, Moray is only available for Dos/Win32, and I don't believe that a Linux port is planned.