Hey man, if. You dig through some of the similar threads here you'll see everyone that's asked has been given this advice: don't forget all the accessories. If you spend all of your money on a camera, the best you can do is a one take, shaky handheld, silent (or really really bad audio) movie. You'll need at minimum a tripod, microphone/boom and with a dslr you'll need an external recorder.
You can start with less and focus on different things, but if your $700-900 is intended for an intro package you may want a less expensive camera and set some of it aside for the extras.
As far as which is best, you have three replies with different answers haha. They'll all shoot good looking video with shallow DOF. Some have better features in one aspect, others in others. Not a solid answer, but yeah man. Good luck shopping!