The list of banned cards on Pokemon.com has a separate section listing the cards banned in Unlimited. Right now, there are no cards listed there.
Note that the Unlimited format consists of all cards that are, or ever have been, in Standard. From Bulbapedia:
The Unlimited format of the Pokémon Trading Card Game allows any card that was once playable in Play! Pokémon tournaments [...] can be used.
Because of the lack of restrictions in Unlimited, decks can use combinations of cards which are not legal in Standard format or Expanded format play. Cards such as Porygon2 and Seeker which never appeared in the same Standard format, are frequently used together.
So, if the cards you named were ever in the Standard rotation, and are not explicitly named in the 'Banned'-list under the 'Unlimited' header, you're good to build a deck around 'em.