You can go easy with 2 GB Ram or even 1 GB. I have Celeron G465 - and this is more than enough. Why such a big hard drive? You can go with used 80 GB hard drive (I've found one for 9 bucks), or you can install Windows 8 on 32 GB USB stick. And I think that 7850 is the best option from all sides. 400 Kh/s on litecoins or 350 Mh/s with bitcoins. Only 150 Watt. Low price. What can be better than this?