I'd be curious to hear what other people offer to this, but my experience with both the Nikon D70s and Nikon D40x has shown me quite a bit.
First of all, the big thing both are lacking is fast writing times. A 30 second exposure shooting in RAW & JPEG can be between 10 to 20 seconds. I own a pair of D40x cameras now and when in a mode strictly for lightning photography, I am using both which sort of offsets the writing times.
The D40x has the higher MP rating at 10.2 while the D70s runs 6ish. However, the D70s has a cable release option that the D40x does not. Both have the IR triggers and with some accessories, could probably be adapted so you don't have to be standing in front of the camera to trigger. Both cameras have modes which shoot to 30 seconds and both also have bulb settings. Again, but have IR remotes available, but only the D70x (out of the two I am speaking for) has the cable release option.
Noise issues with both models are next to non-existant. In fact, both cameras at 30 seconds have hardly any noticable noise at all. Beyond 30 seconds to a minute, things looked acceptable. Beyond that, it gets interesting. Both have noise-reduction settings and shooting at lower ISO speeds is helpful. One thing to note, the D40x goes to 100 while the D70s only went to 200. Again, nothing really that noticable, but worth a mention.
These bodies don't have the bells and whistles as say a D200, D2x, or the upcoming D3 series. I have seen those used in the field and they write much faster. The D2x to which I saw in action took multi-minute exposure with low noise and almost immediate write times. The trade-off for this is obviously price. Again, I've paired up on D40x cameras and likely saved money as opposed to buying one camera.
The D40x is a fairly inexpensive body to which for the price range you're talking, gives you plenty to invest in glass. I recently purchased a Nikkor 18-200mm VR lens with the second Nikon D40x for less than $1350 total (w/ tax). Its on the higher end of your limit, but a good body and a great lens that with the zoom range, you'd likely never have to take off.
A cheaper setup would be the D40x with the 18-70mm lens. That setup would run you well under $1000 and is definitely worth checking out. Obviously you won't get the range as the 18-200mm, but the lens is great. This was my starting lens and it sits on one of the two D40x cameras I have right now.
I would stay away from the 55-200mm and the 18-55mm "kit" lenses. While inexpensive, I have found focusing issues with these at their longer focal lengths. The blur is due to having an issue finding infinity or the camera picking up shaking. In either case, I've lost many shots due to this and am happy to have replaced those lenses with the VR 18-200mm. Again, something else to consider in terms of zoom.
Cameta Camera on Ebay has been my trusted source for buying cameras. Their prices are comparable to many other places and they are very trustworthy IMO. I have ordered 3 cameras in total from them as well as a handful of accessories with absolutely NO trouble at all.
Hope this starts you off well! I'm sure there are some other great suggestions out there to which I'll be awaiting to hear other experiences with other cameras, lenses, and brands.
Best of luck!
Shot with Nikon D40x w/ 55-200mm lens (one of only a few in good focus)
Shot with Nikon D70s w/ 18-70mm lens.
