Help finding the right DS Flashcart for me

Hey there, good people. I'm considering getting a DS Flashcart soon, and my questions are simple.

How much setup do they take? I haven't been very deep into emulation for a couple years now, so I'm a bit rusty. Now, I don't mind relearning and doing the setup, but is there a good place to get instructions if it does take quite a bit?

Also, while looking around I noticed some carts have a bad reputation, so I figured I'd get an opinion here. What is the best flashcart to get?