Hi "Young turk!"

(If your not a Rod Stuart fan, you won't have a clue?)
With a max of $800 to spend, perhaps the 10" dob from Andrews is the way to go. Although if you get the one with the crayford focuser & BK-7 primary, that only leaves you $100 (less postage) for any accessories you might want.
Also thinking an 8" dob may be suitable too. I suppose thinking along the lines of "biggest aperture for your budget" The 10" is more appropriate..