If I were buying it today my choices would be 1st. SB-900, 2nd. SB-800 or 3rd. SB-600. I am using both SB-800 and SB-600 flashes today but with the Beamer I use the more powerful flash (SB-800). The SB-900 is a heck of a flash but quite pricy.
I use the D300. The SB900 is powerful enough, and zooms enough that you can get away without the beamer in many cases. I am not even sure if they have a beamer out for it yet, as the head is bigger.
One of the real benefits of the beamer is faster recycling times, so it still might be worthwhile with the 900.
Personally, I would prefer a pair of used 800s over the cost of a new 900. Two flashes give you more options for other types of photography.
Thanks guys sounds like the SB 900 is the big choice, but the SB 800 would work fine too. Is there a place you would recommend where can I order one that is at a good price. I am in Florida Everglades right now.
B&H does not carry Nikon Flashes from what I can see.
I have a SB-600 and my wife bought me the SB 900 and a Better Beamer for it. I have not used the BB with it yet. I have good results without it. But then again I am only shooting with a 200mm f2 w 1.7TC. I love the controls on the SB 900