As just looked and found that s3d runs on Linux I'm investigating the option to run everything on the integrated Pi and dispense with a PC.
First test it, try to slice with Cura on the Pi and you just don't want to do that anymore (far to slow).
I agree kick2box I haven't tried it myself but some of the more complex models can slice slow on a laptop, the pi would probably be terrible. No harm in trying with a free slicer to get a taste though..