Forensic Gadgeteer

Whenever you cast an artifact spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Activated abilities of artifacts you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Conch Horn

{1}, {T}, Sacrifice this artifact: Draw two cards, then put a card from your hand on top of your library.

Sai, Master Thopterist

Whenever you cast an artifact spell, create a 1/1 colorless Thopter artifact creature token with flying.
{1}{U}, Sacrifice two artifacts: Draw a card.

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When this creature enters, draw two cards.

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Mm'menon, the Right Hand

Flying
You may look at the top card of your library any time.
You may cast artifact spells from the top of your library.
Artifacts you control have "{T}: Add {U}. Spend this mana only to cast a spell from anywhere other than your hand."

Library of Leng

You have no maximum hand size.
If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.

Brainstone

{2}, {T}, Sacrifice this artifact: Draw three cards, then put two cards from your hand on top of your library in any order.