Well yes it is very difficult to know the condition of puppy as it is very young when you buy it.
Try searching for a good recognized breeder, who will guide you through all the pros n cons of the breed.
like you said you are interested in a beagle, to tell you about them they are very active n love to play, also they become very close to their owners, also they like getting your attention n do bark alot at times cos they want to express their emotions to you.
put in a little extra, and since you are a Doc, i dont see a problem with that, but go for a puppy with papers, which gives you a detailed idea of the dogs pedigree, so that you understand what is the standard of the dog you are buying.
I would love to assist you in adding a new member to your family, but i stay in Mumbai.
also i could arrange a loving beagle pup for u