Probably with some good texture maps, to begin with. See if you can find normal maps, spec maps etc.
I wouldn't worry too much about SSS/transmission, other than probably mixing in a bit of a Diffuse transmitter material, to ensure it's still fairly quick to render.
"I still can not render a scene larger than the GPU memory." I don't think your problem is solvable, unfortunately. You have relatively little video memory, yet want to render big scenes. Indigo doesn't have "out-of-core" GPU rendering, and NVIDIA GPUs are known to be more memory limited in OpenCL m...
If you download it to Mac OS X, it automatically unpacks the zip, unfortunately. Go to the folder you just downloaded, open it and select indigo_exporter. Right/CMD click, and compress. Then go to blender and install the add-on from the zip file you just created. Enable it in Blender, save user sett...