We don't know if you already have:
Microphones (there is no single best mic - it depends on the scene). At a minimum, a shotgun (condenser) mic and a couple of wireless lavalieres. Just this could use your entire $850 budget. I use Audio Technica, Sennheiser and Sony (professional) mics and lavs.
Audio recording system: I use a Zoom H5.
Lighting: I use a couple of on-camera LED lighting systems... and if needed, have a couple of light trees and six PAR56 cans with dimmer system and gel sets.
Steadying devices: I use Davis & Sanford ProVista tripods, a Steadicam Solo with vest and articulated/counter balanced arm and a Kessler 8 foot camera crane mounted to a K-Pod tripod and Hercules head... and thinking about some sort of slider system.
Editing is done with Final Cut Pro running on a 27" iMac and 24" Acer monitor connected to the iMac. Video project files are stored on an external 4-bay JBOD hard drive array - each bay has a 4TB hard drive...
Throw in some cables, high capacity batteries, memory cards, external Delvcam camera-mount 7 inch video monitors, Pelican cases, 12 foot square green screen background, teleprompter, boom pole, and a few other items...
Assuming you have at least some of the above, great... or if you have a different budget for the above, awesome. For $850, you are in the mid range of consumer camcorders. There is no dSLR that will do what you want. See what Canon or Sony has at your budget. You are nowhere close to "professional grade" - that said, a pro will learn to use the equipment available and understand not to use it outside its limitations.
Someone with experience and skill can turn out great stuff with inexpensive gear. Someone with no experience can have the most expensive gear available and turn out garbage.
The video capture/storage is only one part of an entire system of stuff that all needs to work together... Forgot to mention... I really like my Sony PXW-Z150... and yes, video is my hobby.
If your stated budget is for "everything", you are getting only a camcorder and somehow think that is all you need, then the only thing I can do is wish you "good luck - you're going to need it."