There arn't many Asus-Intel-PCI-E motherboards supporting DDR1. The majority are DDR2. If your PC is primarily for gaming, why not buy AMD? Also, whats your maxium budget? The first mobo that came to mind, and should suit your needs is an Asus P5VD1-X. It supports SKT 775 Single+Dual Core processors up to 1066fsb, Dual Channel DDR1 400, PCI Express or AGP 8X, and SATA with RAID 0, 1. Not bad for only $57. I've read a few UK user reviews and overall it seems a decent/stable board, and it won't break the bank. I'd be cautious ordering from Newegg though. It seems a lot of customers are receiving DOA's (proly a bad batch so I'd phone them first).
Since you havn't stated a but I'd suggest buying the best (compatable) skt 775 processor you can afford

Edit: If you havn't already bought the Crucial RAM and are adamant to use INTEL. I suggest posting your budget and we'll re-spec you a motherboard, processor, and DDR2 RAM.
GL.