Kodama's Reach

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Boros Signet

Gruul Signet

Cultivate

Selesnya Signet

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Sol Ring

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Solemn Simulacrum

When Solemn Simulacrum enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When Solemn Simulacrum dies, you may draw a card.

Havi, the All-Father

Havi, the All-Father has indestructible as long as there are four or more historic cards in your graveyard. (Artifacts, legendaries, and Sagas are historic.)
Sage Project — Whenever Havi or another legendary creature you control dies, return target legendary creature card with lesser mana value from your graveyard to the battlefield tapped.