After consultation with Chuck from the Nucore team, I was able to gather a list of suitable parts to build the Nucore system.  There would be many other suitable PC components and prices, the main thing is getting a compatible CPU & motherboard without spending more than is really required.  The DVD drive list below, is only required to load the initial Nucore software.  So you could save the $29 and borrow the one from your own PC to install the initial software.  Anyway, below is a list of what we settled on.  I purchased these items from PC Case Gear http://www.pccasegear.com  here in Melbourne, I've listed each item with links to their website so others can see the parts and compare specs if considering doing this themselves.

  1            Vantec ION2 460W Ultra Quiet PSU                    $44.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=15_1110&products_id=11137

  1         Samsung SH-S223C SATA DVDRW Drive            $29.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=658_667&products_id=13068

  1         Seagate Barracuda 500GB ST3500418AS            $45.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=210_344&products_id=13263

  1         AMD Athlon CPU II X2 255                           $75.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=187_345&products_id=1337

  1         Kingston RAM KVR1333D3N9/2G 2GB DDR3    $39.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=186_774&products_id=13719

  1         ASUS M4N68T-M Motherboard                    $56.00    http://www.pccasegear.com/index.php?main_page=product_info&cPath=138_803&products_id=15230
                                                                      
                                                                      Total  $288.00