Didier's script isn't supporting textures at this time. Hopefully it will someday. (SunFlow does but as noted above Didier's efforts in his plugin development are hindered by a lack of documentation on SunFlow). I don't know if there are any other routes to getting a textured model into SunFlow. I haven't looked around the SunFlow site or Forum enough to find out.
If your model has colours they will work fine. I attach an example render. The model is from the FormFont Exchange. After exporting from SketchUp I edited the scene file so the glass and hydraulic rams would look shiny.
http://www.sketchucation.com/forums/scf/sas/Gallery/ross/sunflow5.jpg
The render times for the above image was about 15 minutes. The 'clay' ones above were just two or three minutes. Adding the HDR lighting & then the glossy effect added more time. The glossy one probably took 20 minutes.
If you visit the gallery at the SunFlow site you'll see the program is quite capable. Hopefully Didier's script can, in due course, develop to take more advantage of it.
Regards, Ross