With the DOC removed, the WebSurfer booted fine off my $30 Promise Ultra66 IDE controller.
One good hack deserves another, so I "upgraded" my IDE controller to the $150 FastTrack66 RAID controller using this incredible mod: http://www.hardocp.com/articles/raid/mr_boomys_raid.html
While the new RAID card works fine in my other machines, it won't boot in the WSP. It gets to the Promise BIOS, scans the IDE bus, and then hangs. If I remove all IDE drives, it reports no drives found and continues.
Just a heads-up in case anyone else was considering this hack. Stick with the Ultra66 for WSP.
(I hear people buying cheapo IDE controllers for $20+, might as well buy the best for a few bucks more. Includes Ultra66 cable.)