6 chicks at 6 weeks are going to need a very minimum of 12 square feet, so that'll give you some idea what you're looking for. I brood in galvanized livestock troughs, but understand those aren't for everyone lol. My second go-to is large cardboard boxes. Get two of them, tape them together side by side and cut a door between them. This automatically gives you a warm area and a cool area and prevents the all-to-common problem of chicks becoming cooked nuggets from overheating. Heat lamp on one side, feed and water in the other box. Pine shaving on the bottom, plus when you're done it can all go in the garbage or the compost.