You can find some of those very good Vampire armors on the strongest vampires in random dungeons in Skyrim.
I would go get them but I much prefer the Noble/Royal Vampire armor with vampire gauntlets and boots all legendary.
I'm currently wearing the vampire royal armor, thieves guild hood (isn't visible), enchanted silver circlet (is slightly visible under the hood, looks good), shrouded hood, vampire gloves, vampire boots, bone hawk ring and bone hawk amulet. Looks amazing, I can wear so many head pieces due to the TG hood vampire glitch.
I'm just curious whether the major/extreme/peerless vampire armors exist like uesp say they do, for a future character that doesn't enchant. Have you actually seen them?