Memory Guardian Affinity is never something to sneeze at, especially on fliers
This is a bit like asking whether tires or an engine is more important for your car
Best Art If you want pretty sleeves to fit your aesthetic, Ive got a few suggestions for you

Ashiok's Erasure Assembly Hall Aven Shrine Banishment Bazaar of Wonders Bifurcate Bile Blight Bloodbond March Cabal Shrine Callidus Assassin Canoptek Wraith Cephalid Shrine Chrome Replicator Circle of Confinement Circu, Dimir Lobotomist Clarion Ultimatum Cornered Market Counterbore Crumble to Dust Cylian Sunsinger Declaration in Stone Deicide Deputy of Detention Detention Sphere Dichotomancy Doubling Chant Dragonlord Kolaghan Dual Nature Dwarven Shrine Echoing Calm Echoing Courage Echoing Decay Echoing Return Echoing Ruin Echoing Truth Endless Atlas Eradicate Evil Twin Exclusion Ritual Extirpate Extraplanar Lens Eye of Singularity Frostpyre Arcanist Godsend Grim Reminder Grizzled Huntmaster Harness the Storm Haunting Echoes Hint of Insanity Homing Lightning Hour of Glory Infernal Tutor Invader Parasite Invasive Surgery Isle of Vesuva Ixalan's Binding Izzet Staticaster Kotose, the Silent Spider Legion's End Legions to Ashes Lobotomy Locket of Yesterdays Maelstrom Pulse March of Burgeoning Life Mask of the Mimic Mechanized Production Mimeofacture Minamo's Meddling Mindreaver Mirror Box Mishra, Artificer Prodigy Mocking Doppelganger

You might find a 3D printer you can use to make your game at your local university, a design firm, or a model building company
You can open Phyrexian Urabrask in Set, Draft, and Collector Boosters, in both non-foil and traditional foil