[roach-commuter]

https://www.neurotica.com/misc/SunPCi/

It's not my site.  The link was posted to one of the Sun mailing lists a couple of years ago (by that site's owner).  Versions 1.3, 2, and 3 are all there along with some other relevant stuff.

Thank you again.
Update: I was able to install the Sunpci1.0 card using the Sunpci 1.3 software from that link. I also replaced the stock AMD K6-II 300 Mhz cpu with a 400 Mhz one. I couldn't find any documentation on how to do it but it turns out it's enough to pull 2 jumpers from the JP4 group. Namely 3-4 and 5-6 and only leave a jumper on 1-2 and that's it.