Roddy Strang is probably one of the best NH type trainers in Area II. He is up in SE PA. He’s very good. He also Fox Hunts and his wife events so he understands English too. I’ve sent him a problem child before.
Some trainers are better with quirky than others. You could also free lease him. That way you have a chance to prevent him from ending up in a bad place. That said…most horses that I have free leases came back worse trained then when they left and I had to do quite a bit of remedial training to get them back where they were. Me…I’ve been the one that bought the “bad” horse. And they became one of the best I have ever owned. Your guy doesn’t sound that bad to me but one who has to be managed. It’s totally fine if that isn’t suitable for you…but If me…I’d put him with someone like Roddy for seriously 6 months. And then see what he says. This is Not the sort of problem that is fixed quick and takes the right rider to desensitize.