Why you want to build a P3 in current days? Do you have a 1 GHz or faster P3 with 512 MB or more SDRAM? Otherwise I see no reason for building P3 system today. Remember, P3 platforms are completely outdated and SDRAM is expensive and harder to find nowdays.
I recommend ASUS TUSL2-C. This board uses SDRAM
<b><A HREF="http://geocities.com/spitfire_x86" target="_new">My Website</A></b>
<b><A HREF="http://geocities.com/spitfire_x86/myrig.html" target="_new">My Rig & 3DMark score</A></b>