Considering how fast SB is supposed to be, I'm not sure you'll be able to squeeze one into an $800 build.
To answer your question you can also buy a case, PSU, GPU, and Ram as well. A triple channel Intel kit should be fine. Even if SB supports quad channel as some suggest triple channel will still work fine.
Thanks for the response. $800 doesn't include OS, btw. Also, all the "rumor" prices are still within the low $200s for the lower SB CPU and they wouldn't be mainstream if they were all really expensive. In any case, I'll up the budget a bit if I need to (within reason). I won't know until the prices are revealed.
I heard SB uses dual channel RAM? Maybe I should just wait and see about the RAM. I'll be on the look out for deals on those other parts though.Edit:
(Was writing the above when vindictive posted.)
I didn't count on the motherboard being that expensive. If it turns out being too much, I'll probably go with an i5-760 from Microcenter, not AMD. That reminds me, I wonder if MC will have SB chips cheaper...