That's an interesting question. I've never studied grammar, but I do have a pretty good understanding of it, and my guess is that the second is probably technically correct. However, the first form is probably the one you will hear most commonly!

For me "All you need are" sounds very strange. I guess you should say "all you need is" because in this case "all" is a synonym of the word "everything". One couldn't say "everything are", it would be incorrect. Although you could either say "There are different things that people use to learn. All you need are patience and practice". Therefore, "all you need" depends on the context.

I think that both are correct, but it'll be better when you use the first option with "is".