I can also recommend the D300, I've got no complaints with mine at all, and I've been fairly happy with the performance at high ISO's. I don't really see much justification in going for a D300s unless you want the video shooting, which personally I don't!!
This shot was taken at ISO 1600, just for interest
There's only a small bit of noise evident in the darker areas of the background, and I personally don't think it's that bad or obvious.
