I've worked with Sparcs for over ten years, and I don't believe I've ever used a floppy on one. Just don't worry about it. Especially since I'm 99% sure that they use a proprietary floppy drive.

I'm not sure what you want to know about the SCSI/Ethernet card. I can tell you that those cards were very common. At the time, you pretty much had the option of the SCSI/Ethernet or a quad-ethernet card if you wanted an ethernet NIC. At the same time, I don't know if it would be a 10BaseT or a 100BaseTX NIC (which would be an le or hme, respectively, under Solaris), nor do I know the type of SCSI adapter it would be.

You can certainly use the Plextor CD drive with it. In fact, Plextor is generally recommended because it's one of the few CD drives manufacturers that always put on the option to switch the drive to 512-byte (or is it bit?) blocks, which is required if you want to boot off of it. Make sure to change this (it's usually a jumper on the back) if you need to boot from it.

Don't know anything about where to find cables in the UK; sorry.

Are you interested in keeping SunOS/Solaris on them, or do you just want to reinstall? If you want to keep SunOS, I can provide some suggestions as to how to reset the root password.

The only other suggestion I have is to consider if you really want to run Linux. NetBSD and OpenBSD might be interesting to you, as well. Most of the advantages Linux has over other free Unices get thrown out the window when you're not running on an Intel machine. (Even emptool won't build on them, as I found out earlier today.)