ETA my colt by Bon Balou is the one that has the hunter trot!
Harvard. He is in Canada.
I have a gelding of his and he is often the hack winner. Very ammie friendly too. He has never bucked or stopped with me, just goes on like okay dokay.
We have Navarone and his offspring. Not heard from any of them that have difficult temperaments, but probably not telling me or no stallion can fix every mare. There is/was a thoroughbred stallion named Navarone so that could also be a confusion. Navarone can throw chestnut though. Good cross with Galoubet too. Are you looking for fresh only or will you consider frozen?
I second Harvard. I have a very ammy friendly 4yo who has won every hack he’s been in. Harvard is dressage bred but will produce VERY fancy hunter movers and will not take away the jump from what I’ve seen. Chad Keenum has sold a few very fancy Harvards I believe.