Sorry those were meant for Arinoth. I was about to edit and quote your original post but that seems like way too much effort right now :P
1. NCIX.com - Buy ASUS AT3IONT-I Atom 330 DDR3 NVIDIA ION mITX 1PCI-E16 HDMI Video Sound GBLAN Motherboard - AT3IONT-I In Canada. NCIX.com - Buy Zotac NM10-B-E MINI-DTX Atom D510 NM10 Express PCI-E16 PCI-E1 SATA Wifi Video GBLAN DDR2 Motherboard - NM10-B-E In Canada.
Unfortunately, Atom boards almost exclusively come in Mini-ITX (I recall seeing mATX but that was a while ago and I don't think it's being manufactured anymore) and those two were the only ones I could find with a PCI-ex4 slot or bigger.
2.
When you say GP drives, do you mean Caviar Green or the RE4-GP? If you mean Caviar Green, you might have an issue since it does not support TLER but if you are referring to RE4-GP, it should be alright since it does support TLER.