With $800, Maybe 50-50 but I would prefer to spend more on the preamp. At this budget, you'll have to consider an 80's classic amp and there are several in the $3-400 range like PS Audio or B&K, then I would match it with a nice Dyna PAS 3, they are extremely musical.
If it were me, I'd jump right on that PS Audio 2C+ and the Dyna PAS3 that are now on A'gon. If Audiomart, I'd look at the Musical Design, Apt Holman or PS Audio 100 Delta and the Blair Chapman tube preamp or the other custom tube preamp - I think any of these would smoke an integrated....
With $400, definitely Integrated is the way to go. On Audiomart there is a 300B SET int amp for $450 that would smoke everything away. In fact, I'd probably take that over the $800 separates