Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Yoshimaru, Ever Faithful

Whenever another legendary permanent you control enters, put a +1/+1 counter on Yoshimaru.
Partner (You can have two commanders if both have partner.)

Springleaf Drum

{T}, Tap an untapped creature you control: Add one mana of any color.

Paradise Mantle

Equipped creature has "{T}: Add one mana of any color."
Equip {1}

Thrasios, Triton Hero

{4}: Scry 1, then reveal the top card of your library. If it's a land card, put it onto the battlefield tapped. Otherwise, draw a card.
Partner (You can have two commanders if both have partner.)