Re puppy buying: Does this ring true?

I am still gingerly considering getting another dog. I would consider adopting but since the last experience came back to bite me, I am also somewhat open to buying a dog. I found a cute maltipoo online. Supposedly the Web site – which I had been in touch with before – represents many breeders. Although this site was listed as “maltipoos – NJ”, the pup is actually in Lousiana. I said I would not consider buying a puppy unless i could meet it. The puppy counselor told me that no reputable breeder would let someone come in to meet their pups because of Parvo – that this was only done at puppy mills. I smell a rat – am I right or wrong? Bonus question: how should I be looking for a dog? I do look at petfinder.com and would prefer an older dog but…once bitten, twice shy. And I think I need to wait a year anyway.