Here's my newegg list:

Master: Celeron E3300, G.SKILL 2GB, Supermicro MBD-X7SBL
NAS: Atom 330/Supermicro MBD-X7SLA, Norco RPC-230, Diablotek PSDA500, WD800 HDD, Crucial 2GB
Nodes: i5, Mushkin 2GB, Supermicro MBD-X8SIL

I'm going to have both the master and nodes boot off the NAS with PXE, and mount NFS shares as root. I figure that that NAS won't have more than 10 connections total, and the most intensive thing will be streaming an HD video to another PC, so the atom 330 should be just fine. I'm also hoping that since the Master won't be participating in the cluster, just managing the queue and such, the Celeron core2 should be adequate. If this is the case, is it possible that I could just have another Atom 330 system as the master?

Thanks guys for the help!

P.S. I don't have any experiance with Atom CPUs, but would the 330 struggle if it had to do software raid 1 and LUKS AES 256-bit encryption?