I was thinking about this thread yesterday. It sounds like there are two goals here:
- breed a successful top level hunter (aiming for the derbies and performance it sounds like)
- have that baby be registered somewhere in case it’s a colt and is breeding stallion worthy
Both goals are to be accomplished with a foal out of the mare OP already has. In my opinion, 2 is a non-starter without 1 - and while I love me a good TB, that’s a really lofty goal for a full blooded Thoroughbred. If the goal was eventing or jumpers, I’d be more optimistic.
Breeding is such a crapshoot, so you need to start with an excellent foundation. Is the mare out there winning in the hunter ring at anything close to that level? Does she have the step, scope, brain, and movement? What about her would you be looking to improve with a stallion? (You don’t have to spell these out for us, but you SHOULD know the answers.) You may find that none of the sport TB studs you have access to have a record of improving those things… but maybe a WB stud does. Plenty of registries have traditions of admitting good TB mares - if she’s quality for the job, this is a very normal path to getting a registered foal.
It sounds like you, OP, have a mare you would like to breed and a stallion in mind already - the sticking point is that you want to be able to register the foal. If the mare and stallion are well suited to your MAIN goal (performance hunters), and to each other (the real key here), it sounds like there may be some options… but it also sounds like you probably need to wait to see what the stud gets approved in first. Personally I’d choose a proven stud for this baby, one with a record of producing UL hunters.
What I would ACTUALLY do is buy the highest quality colt from the best hunter bloodlines I could find and skip all the guesswork and gambling that goes into breeding. I’d spend that money and energy producing the baby for the hunter ring - you’re going to have to do that anyway, so why chance it?