A little further north, check with Molly Rosin who rides a lot of ponies herself and has kids. Full Moon Farm in Maryland has lots of good juniors. Gammon Nuckols in VA has good juniors as well. Check to see who idoes training stuff for some of the pony clubs in those areas as well as with the pony clubs
Lastly - and this one may seem a bit odd/off - I'd contact Dodon Farm. Yes, they are the big-bad-sporthorse go-to guide - but Stewart has also sold some nice ponies lately. (Shhhh) Looking at the website: Dots on Spots, Sassy Sister, Maestro's Bardic Gold...) He may have some secrets of the trade, depending on the degree of your pony's scope.