Nvidia chipsets have issues with lan not just on the Asus boards, 5 will work fine then you get one that doesn't the AMD CPU boards seem to less problems with it then the Intal CPU Nvidia boards.
For the ram I would use these
http://www.newegg.com/Product/Produc...2KIT25664AA80A
Pull the side cover off and have a look at the label on the PSU 500w is getting small for a Quad and a 8800GTS.