You would have a hard, but not impossible time finding a used loader. New ones are easy though; go to any tractor dealer or service shop. Bush Hog, Woods, and others have brand new loaders with mount kits for your tractor.
Be ready to spend $3000 or so installed though..... I have a Bushhog 1846qt on my b8200, it is the Bushhog model that would fit your. It works well.