Well, Supermicro's P4SBR is for P4 with SCSI...but it uses SDRAM memory, it's designed for a 1U chassis... They have several P4 Xeon boards though that use DDR, if you wanted to pay for a Xeon. 🙂
Oooh, they also have the P4SGR. Uses the 845GE chipset, seems to be what you'd want.
Most of the time, anybody that needs SCSI on-board these days is looking for a more high-end board, which is why so few single-processor boards have it now. In the past, "workstations" would need SCSI for best performance, but still only need a single processor. Now, UltraATA drives let "workstation" class boards perform without SCSI, so mostly "server" class with multiple processors has any need for it. You may have been looking for a "desktop" board, but you need to look at the "workstation" and "server" boards to find anything with SCSI.
MSI also has the 845E Master-LR board (MSI-9129), but that doesn't have an AGP slot. Also the 845 Master-LR, just without 533MHz FSB support.