I understand that you need to run four colors to pull this off, and Im not sure if Standard has either the manabase or the cantrips to try to move in on that approach, but Modern should easily have all the necessary tools available (not really considering it for Legacy as combo decks have a much higher bar to climb there, what with Tendrils of Agony and Show and Tell alive and kicking)
Gemstone Caverns is not a card that gets a lot of reprints, making it extra valuable
That draw trigger isnt just flavor text either
These come in white boxes, as pictured above, and all 100 cards inside are foils with a special Surge pattern
But still its great, being able to deal with cheap creatures and also shooting it straight into someones face
Yes, planeswalkers can be commanders, but only the ones that specifically say This card can be your commander are allowed to lead a Commander deck