Dual purpose breed means you plan on eating them by the end of...one year? two years? Then ordering more of the same the next spring?
If you plan on having the flock stored in the freezer over their second winter that is when you can do a SUPER CLEANING of your coop and let it dry well for the following spring's chicks.
Myself, in your shoes, I'd have the minimum size coop and the maximum size yard(s). The coop can be the chick's home by week two of age, and once they discover their yard they will spend the majority of their time in it, rather than the coop. Their poop will be most concentrated under their roost so designing a system of easy cleaning that area is vital. All their food and water can be in their yard and if the coop is built up off the ground by two or three feet, their yard can include underneath their coop.
Any coop and yard, no matter where it is built, must take into consideration predators,,,coyotes, foxes, hawks, owls, possum, snakes, etc all want to eat your chickens. chicken wire keeps your chickens in but will not keep the predators out. They will try to break through, dig under, climb over or just reach through your fencing so your largest cost in money and time is building everything safe.
This section of BYC has hundreds of coops members have built...some for very little out of pocket. Members here have delt with every predator imaginable, every weather type on the planet and every breed of chicken out there.
Chickens can be raised with a lot of daily intense hands on or left to be on their own, depending on what your personal lifestyle allows. They should be a pleasure, not a pain in the patootie. Caring for them should not be a daily struggle of cleaning and fixing their coop, yard, health issues, behaviors...as long as you meet their feeding and housing requirements.
I was told by my grandfather many times..."you always get the dog you deserve" and that is also true for chickens!
Much luck but beware of "chicken math". They are as addictive as pistachios!