Battle for Baldurs Gate will be Wizards rededication to this style of play when the set drops on June 10th
I think he'll love Thousand-Year Elixir and you could add in other tappers too like Arcanis the Omnipotent or Avatar of Woe
Graveyard hate: At least one or two pieces, because graveyards are basically second hands now
Celebi ex and Venusaur ex are two powerful choices that can leave many other types in the dust due to their overwhelming damage
(I looked at Retrace but there aren't many decent in these colors, just Worm Harvest.) Lands that cycle (you'll get them back) I considered mass land destruction, but honestly the deck doesn't need it, and just makes the deck a target
It can still be slow and low-impact against decks that go way over the top, like Green Devotion, but if you just pay attention to how you feel when your opponent casts it against you on turn two in Limited, you might realize that the impact of that card is high enough that it demands serious exploration in Constructed