I am aware that I am late to the party but this is a topic that I am greatly interested in personally, and have been working on a timeline off an on for a while on with just this scenario.
First of, yes, it can be sold. Whether anyone would buy it is a completely different question.
I however believe 100% that the Americans would pounce on this if given the opportunity. Whether or not the Americans could subdue the island, I am confident that the Americans would THINK that they could subdue the island. Remember, Jefferson is president, a man whose military prowess though that gunboats could defeat the British navy and that conquering Canada would just be a matter of marching.
Two points were raised in previous posts: militia doesn't like invading foreign territory far from home and that Jefferson was opposed to large standing armies. If the United States owns Haiti (Saint Domingue/San Domingo, or whatever the Americans decide to call it), then the militia isn't invading a foreign territory at all. Plus many of the southern militias would probably jump at the chance to put down a slave rebellion (pure conjecture). Jefferson's opposition to large standing armies wouldn't be too difficult to overcome because the army would be relatively far away, not like it is based in the United States or even near DC.
I also think yellow fever would be less of an issue (though still a major one) than it was for the French. Yellow fever outbreaks were common in the United States, particularly in the south, which means that many of the soldiers, especially southern ones but even some as north as Philadelphia, would have built up an immunity towards it. Yes it would decimate troops from the north, but it wouldn't be quite as catastrophic as it was for the French.
Unlike the french the Americans would also be able to reinforce much easier, without having to cross an ocean and fight off the British.
All of that having been said, could the American's have done it? I think yes they could have if they had the political will to see it through, because it would be nothing short of a bloodbath. Gallatin would be complaining about the drain on the treasury, but I think that it is just too valuable a prize (it was at one point the most valuable real estate in the western hemisphere, there is no reason to think that it would not reclaim at least some of its former glory if it was pacified) for the Americans to give up on. I do think though that it would make the treatment of the Native Americans look genteel when it is done though. I can't imagine what race relations would look like. It very easily could go the other way though, and the Americans would have their bloody nose of an early 19th Century Vietnam allegory.
Two butterflies that I think are interesting. First: An American Haiti means that there is a significant army and possibly navy buildup before war of 1812. I assume the war still happens, but now the Americans are more prepared for it. Second: The Americans got a little liberal with the reading of the territory covered in the Louisiana Purchase treaty and ended up claiming that West Florida (now the Louisiana Florida parishes) were included in the treaty. The first successful rebellion against the Spanish in the New World was the West Florida Republic that lasted a few months before the Americans...intervened. I could see the same thing happening on a larger scale with the eastern 2/3 of Hispaniola. This could kick up a problem with the Spanish and set back relations even further.