I think this should guide you well. http://www.anandtech.com/show/2716
Although this article is about DX11, it would certainly boast about DX11.
I would say the option two is fine for now. Since DX11 optimized games are very few in the market now. But later when it becomes more dominant, sell off the GTX260 and get the GTX460. This is only keeping budget in mind. But it would also be good, if you get a GTX470 and SLI later. More powerful, but a little less value for money.