Good DSLR camera for professional photography?

I'm currently using my Sony HD video camera for photography as well. It's a good camera, but i'd like to upgrade to a good dslr. Nikon or Canon preferably.between $400-$800 not looking to spent a thousand dollars on one, but i'd like a good one as well. Any suggestions? I'll be doing everything from portraits, scenery and environments including underwater with a housing. So i'll need a camera that can handle a wide range of variety. Also a good lens, good flashes. I have an idea of what I need, but don't really know where to start. So a good dslr camera, lens, and flash.

The professional camera most used at this time is the Nikon D3 or D3s and once in a while the Canon 1Ds series cameras

At $400-$800 you will not find a professional any kind of camera

What you can find is the new Nikon D3100 dSLR which also has Full HD (1080p) video and one of the only medium priced dSLR's with auto-focus in the video mode. $700 with lens

http://www.nikonusa.com/...D3100.html

I hope you know that to shoot the subjects you listed, you will need a variety of lenses and that will add to the cost of your camera system

The standard zoom lens, the 18-55 mm lens will shoot portraits, however if you really get into it, you will want to buy the fine AF-S 50 mm f/1.4 later.

For landscapes (scenery) you will eventually want a super wide angle lens like the 10-24 mm and most underwater housings made for dSLR cameras cost in the neighborhood of $1200 and up.

Nikon has excellent dedicated flashes for there camera dSLR cameras system and over 60 different lenses.

http://www.nikonusa.com/...index.page

Camera systems are built over years of careful planning and growth as a photographer.

And exactly what do you mean by "professional photography"? Are you looking for a camera that will give you photos that look better than what you're now getting or are you in a position to start being hired for shooting pictures?

Better looking photos and video - here's a good place to shop. Http://www.bhphotovideo.com/
Professional photos - you'll need a budget of at least $3, 500 or more.

Have a look at Canon EOS Rebel T2i 18 MP CMOS APS-C Digital SLR Camera
* 18.0-megapixel CMOS (APS-C) sensor;
* DIGIC 4 image processor for high image quality and speed
* ISO 100-6400 (expandable to 12800) for shooting from bright to dim light;
* enhanced 63-zone, Dual-layer metering system
* Improved EOS Movie mode with manual exposure control and expanded recording 1920 x 1080 (Full HD)
* Wide 3.0-inch Clear View LCD monitor;
* Dedicated Live View/Movie shooting button
* New compatibility with SDXC memory cards,
* Plus new menu status indicator for Eye-Fi support