Own a Sony a200 and looking to upgrade possibly to another brand of camera?

The a200 was my first dslr I bought a few years ago. Now I feel as I'm growing as a photographer the sony is slowing me down. I need more from a camera as it is my right hand. I shoot in a lot of low light situations and the sony image quality is not good in ISO 1600 and 3200. My budget is just under a grand but I'm open to more expensive options. I suppose I'm looking for a professional grade camera for a poor photographer. I had been looking at the nikon d90 because I read reviews that image quality is great. I also think the video mode is pretty nifty. Any help and suggestions are greatly appreciated.

Most cameras don't get fabulous shots beyond ISO 800. Grain gets in the way. I suggest you look at a fast prime lens first like this.

http://www.bhphotovideo.com/..._8_DT.html

If you want a faster one, see this.

http://www.bhphotovideo.com/...f_1_4.html