I'm surprised that it seems one cannot get a new SB 800 anymore unless they want to spend more than what an SB 900 costs.
I'd jump on this one from Cameta,(a trusted dealer), Isn't new but you mint is as good as it gets and will be less than the sb900 new. http://www.cameta.com/index.cfm?fa=d...b%20800&used=1
You might think it is more flash than you need, but you'll soon find that it isn't.
If it costs more than you want to spend, eat less. Its the best deal I could find from a trusted dealer.
Make sure you check the dealer ratings in the "dealer feedback forum" if you find a deal too good to be true.
You could go sb 600 but won't get as much and eventually you'll want better, especially for weddings.
What lens are you using? Another option is to try a 50mm f/1.8 or f/1.4. These would allow more low light shooting without a flash.