Nice piece of hardware you have there. I've always loved the Quadra 950's case and abundance of Nubus slots. I have a Quadra 650 myself that's been going great for years now and is running as a web server using MacHTTP and Mac OS 8.1.
Anyways, have you checked to make sure you don't have them on the same SCSI ID numbers? Also, are you sure that the external drive is terminated?
As for taking those drives and connecting them to your iBook or PC, you may have to use some sort of SCSI-to-USB adapter. Be aware of the number of pins that the SCSI interface is using on either hard drive as well. As it is, they seem to be hard to find since
this was the only thing I could locate on the web.
As for external enclosures, there were only a handful that I found on NewEgg.com. Check this list out and one of these might suit you:
http://www.newegg.com/Product/Produc...nd&Order=PRICE
Good luck.