While you can use Silk Touch to get exact blocks, such as Ore blocks themselves instead of what they drop, this enchantment should be prioritized for getting unobtainable blocks.
How to Use Silk Touch Mine Unobtainable Blocks
You'll have to level up other Villager types to obtain their enchanted stock. Librarians will be your best bet since you can trade Emeralds for enchantments even at Novice levels. You'll be able to trade items with villagers to obtain Silk Touch.