We don't know what the D3 reqs will be.
So, for now, I'd recommend an AMD X2 platform with built in HD3x00/HDMI, and a PCIe slot to upgrade to whatever card is needed.
Case can't be a slim if you want to be sure you'll fit whatever card is needed for D3. I doubt a slim card will do very well with it, although we don't know for sure.
Mobo: (w/ HD4200)
http://www.newegg.com/Product/Produc...82E16813138156 - $60
CPU:
http://www.newegg.com/Product/Produc...82E16819103688 - $61
So, for now, I'd recommend an AMD X2 platform with built in HD3x00/HDMI, and a PCIe slot to upgrade to whatever card is needed.
Case can't be a slim if you want to be sure you'll fit whatever card is needed for D3. I doubt a slim card will do very well with it, although we don't know for sure.
Mobo: (w/ HD4200)
http://www.newegg.com/Product/Produc...82E16813138156 - $60
CPU:
http://www.newegg.com/Product/Produc...82E16819103688 - $61