Dan
Not sure where you can get the POH type of material directly. An "indirect" suggestion would be to go to the used airplance websites, try
http://www.globalplanesearch.com/view/all/All.htm
Some for sale adds have very good panel photos, some may also show the switch panels.
All the key avionics items from Garmin and Bendix-King have manuals online you can download from the company websites.
rgds
421C