Greater Fire Protection Potions. We clear MC in about 2 hours. I use one on Geddon. And one on Rag.
Arcane Elixir / Greater Arcane Elixir. Spellpower increase, Depending on what you can afford.
Flask of Supreme Power. My guild has people farming black lotus like mad to have the entire raid flasked, which allows us to clear in 2 hours. They farm and mail it to us for 40g (50% off AH price) every week. This is overkill, they are expensive and you dont NEED them for MC. It’s just for maximum parsing.
Thats really it.