While the GPS496 is a good value, I'd still get the GPS696 due to the size of the display, features, and overall capabilities. Also, much easier on the eyes and you can find some good deals on them as well.
In either case, have it wired into the planes power, mount it with a Angerole mount, and you're pretty much good to go. I also have mine wired to receive cross-feed from the panel mounted GPS.
Regards,
Ron