What nikon or canon camera is good for under 500 but can have the zoom lense changed out?

Also in trying to put a wide lense like what's used to make movies and music videos do they even make those for these kind of cameras?

Not for that money… You'll need a lot more.

Nikon D3100, Canon T3
http://www.amazon.com/...zon.com/s/

At that price the cameras are entry level, so the manufacturers assume you need a beginner lens. They rarely offer a body-only package. The typical 18-55mm kit lens is pretty useful. A model that is a step up is more likely to be an upgrade for buyers who don't want redundant lenses, and therefore likely to be offered in body-only as well as body-with-lens kit options.

500 what? Rupees? Pounds? Yen?

Ahum why only Nikon or Canon

Seriously why only Nikon or Canon.sure they are the big two on the DSLR market BUT and its a big BUT there are other camera types. Like System Cameras, they tend to be quite smaller then DSLR's, weight less, less bulky and yet have a decent sized sensor. And important you can interchange the lenses.

I can suggest you look at the Micro Fourth Third system from Panasonic, Samsung and Olympus. The early models are pretty cheap to get now and you can get a pretty nice 14-42mm lens for pretty cheap to. A good start in photography.

It is lighter and smaller then the big DSLR"s are so you probably will take your MFT camera more with you. And the sensor size is very decent so you still get to enjoy the great image quality.

So there you go look into the MFT line up and you might find the deal of your life, a nice body and a nice less. Maybe even an EVF or Flash for free with it. [well free as part of the deal that is]