For that price range, you won't be able to get a good scope with the special glass/coatings that reduce color distortion, etc (ED glass, I think it's called) that makes viewing wildlife at longer distances more true to life. But, you can still get a very good scope for that price.
I've got a Nikon Prostaff 16-48 x 65. You can swap the eyepiece for an adapter to a Nikon camera, don't know if there are adapters for other cameras or not. Price comes in at well under $400, and if you want bigger, there is a 20-60 x 82 that comes in a bit under $500.
I've been very happy with mine, should serve you well for your needs.
I posted a review of the various scopes I compared before buying mine, you might take a look if you are interested. I had some surprising results...
Anyway, post is here:
http://www.gboreloaded.com/forums/index.php/topic,147020.0.htmlHope it helps!
Just a Shooter