Hi Grant,
There are lots of woodworkers around here who will be able to help you out with any design issues related to SU.
As for rendering, there are a whole bunch of external rendering softwares - some more or less integrated into SU, some free, some cost a bit of money, some extremely expensive.
Here is a link to a list of rendering applications.
I myself have only tried out Podium (which is a not expensive, nicely integrated and easy to use renderer) and Kerkythea (which is also integrated, a bit more complex but free renderer) so far.
There are people however with much more experience than me.
Welcome to the forums, by the way... π