Gigantosaurus I know it might be weird to see a vanilla creature like Gigantosaurus so high on this list, but even without an ability this green fatty is very strong
Most Canadian orders are delivered within 1-2 days
I recommend Facebook Marketplace as a starting point before transitioning to something a little more concrete
Instants and sorceries dont go until the graveyard until the final step of resolving, so they wont count itself in your graveyard for threshold
Kaldra Compleat (pack foil $13, sketch foil $10) There is a Spotlight Series for $120+ but I dont think its worth buying as a speculative purchase
Of course, there are some high-synergy cards that you probably want to make room for in your Urza deck: Etherium SculptorEtherium Sculptor and Foundry InspectorFoundry Inspector, Sai, Master ThopteristSai, Master Thopterist, Thought MonitorThought Monitor, the monocolor Urza, Lord High ArtificerUrza, Lord High Artificer, Urza's SagaUrza's Saga, and at least four artifact lands