If you're interested in an internal scandoubler, I have one.
It can be used together with the Cybervision 64/3D or as a stand-alone scandoubler.
It's in great working condition, but I bought a Picasso IV, so I don't need it anymore. :-)
http://www.amiga-hardware.com/showhardware.cgi?HARDID=447Send me a private message if you're interested. :-)