I'm not trying to start a Flame war or anything of that Nature. (I like Nikon - because that's the lens set that I have. - Canon makes a product that is equally as good.)
I don't think you can go wrong with ANY of the canon or Nikon DSLRs out there - the easy choice though - if you have Nikon Lenses, and IF they will work - Go Nikon. I think the D50, D70, and possibly the D100 are all at or below $1k.
I've just upgraded to a D2x and have a D100 and D2h. All of them have been excellent cameras. (although I have to get rid of something as I only have two hands, how can I justify three cameras.)
Northwest Glocker #919
G1 Niner #80