I'd personally start off ridden hunter (No jumping) to get you and him used to what to expect and once he is setlled with that then go onto working hunter.
I do ridden cob and working cob with my boy and in working cob the style of jumping counts for a lot of points so if you get you ridden right even if he does messy jumping then you will still be towards the top of the line up.
My boy is a nightmare as some days he goes round jumps like a pro and other days he just thinks everything is out to get him.
Thank u everyone, I think I will try the ridden hunter (pony) if I can find a class and work on our jumping so I can do some working hunter next year as he does jump well but tends to rush into the fence often inverted so quite a bit of homework to do, but to be fair on him he has only been backed 18 months, tho 8 yrs old he was a driving pony so he's doing well in my book, and most importantly I love him to bits!