Stainless is always best, but aluminum is also just fine. The biggest difference is the quality and fit of the handles. The aluminum pots tend to loosen the handles if filled and lifted very much. Alli also requires a good layer of oxidation on the inside surfaces to avoid the tangy taste it tends to leave. Fortunately the oxide layer is super easy, just boil a couple pots of plain water and it's done. If you can afford the wallet shock a 10 gallon stainless is ideal for a new comer to grow with. Otherwise do the largest pots your budget will over and call it good. I had found a vendor that was cheap but have experienced poor service and am still waiting for it to arrive after 2 weeks. Welcome to the addiction, I caught it doing my first batch in a Mr Beer set up and have been trying to get to all grain as fast as I can go on a disabled persons budget. Hope this helps.