I had a 08 845 for about four years. I replaced it with a 830. I used a 18"
extension with the 845. I also use the 18" extension with the 830, mostly towing a 6x10 enclosed trailer. With a 9.75" ball mount, the ball is within 1-2" of the end of the camper. At other times I have used a ROLA polypropylene hitch cargo carrier that easily clears the back end of the 830. Your picture suggests you have a standard(6'9")bed which is the same length Super Duty bed on my truck.If your hitch weight is going to be under 200 hundred pounds as you stated, I think you could find a workable solution with your present receiver and a 18" extension.