Don't get a 1090T. Get either a C3 stepping Phenom II x4 or an i7. For gaming, the Phenom II is definitely the better choice, but the i7 will be noticeably faster in a few things, such as photoshop and video editing.
Also, I still recommend a 5850. They are epic price/performance cards, and they overclock like crazy if you get one with vcore control.
EDIT: This pretty much says it all. The 5850 is incredibly close to the 6870 at stock clocks, but it costs quite a bit less.
Once overclocked, the 5850 beats the 6870 because the 6870 seems to have very little overclocking potential compared to last generation's cards. I've seen 1000 MHz + on 5850s before.