There are currently 2 different Potion Types (Health, Mana) and 3 Different Levels (Low, Medium, Strong) in the mod.
The Low Mana Potion and the Low Health Potion can be bought from Alchemist for 45 or 50 Gold Coins, though Regeneration and speed potions can be brewed using the sugar and ghast tear he sells you. It's also possible to make a strength potion and a potion of fire resistance using blaze powder crafted from the blaze rod from blazes and magma cream from magma cubes, both found at the volcano.
Low Health Potion: 30 Health Regen Med Health Potion: 100 Health Regen Str Health Potion: 300 Health Regen
Low Mana Potion: 30 Mana Regen Med Mana Potion: 70 Mana Regen Str Mana Potion: 200 Mana Regen
Low Mana and Low Health Potions can't be crafted, they have to be bought from Alchemists.
Level 2 Potions:
Level 3 Potions: