Hallowed Fountain

({T}: Add {W} or {U}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Exotic Orchard

{T}: Add one mana of any color that a land an opponent controls could produce.

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

You have no maximum hand size.
{T}: Add {C}.

Counter target spell. Untap up to four lands.

{T}: Add {C}{C}. Activate only if you control five or more lands.

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