It's an ASUS Maximus Formula. One of 'em gaming motherboards. The mobo I originally wanted was the P5E (based on the same X38 chipset, but not labeled as a gaming mobo), but my dad upgraded it for me.
Rest of specs in previous thread: http://amdusers.com/forum/showthread.php?t=4934
As for AMD or the Quad, I can't really say since I haven't had an AMD for several years since I had the Athlon XP 1700+ 1.4GHz.