For 6 birds, you need a 4x6 coop minimum (figure 4 sq ft per bird on interior space). As to your weather, it's ambient temp that matters and you are mild (I grew up in Iowa) so insulation is not a requirement as long as the coop has a tight roof, is not drafty but it MUST have ventilation for summer heat and winter moisture and ammonia fumes that accumulate. You should plan a coop that you can either walk inside or that is accessible for cleaning and maintenance. Crawling in poo is not fun. All a coop really provides is a place to roost that protects from the weather, a nest box and feeder can really be anywhere that they are dry and water fount can go anywhere but remember it has to be heated when temps are below freezing and refilled a couple times a day when it's hot so it should be easily accessible.
Suggest you build for the heat with large open panels for air that are covered with 1/2" hardware cloth and when the weather goes bad, simply close doors & windows or cover the openings and the birds are sheltered. Old wooden frame windows hinged over a wired wall opening make great opening covers as well as letting light and winter sunshine in. Another idea would simply be to reinsert the cut out panel from the vent openings for the winter. Avoid a design with vents that allow cold air to draft directly on the bird's roost as they will sicken easily,like a kid, but again you must have some winter ventilation.
For a easy run, use a pre-fab chainlink dog kennel and attach a additional panel for a top cover to keep hawks, owls, and coons out and it makes a nice roof to lay a tarp on for shade. For 6 birds at 10 sq ft per bird you need 60 sq ft minimum, but if you put your coop inside the kennel, then you will have to go correspondingly larger and chickens would love it if it was even bigger. Remember to skirt the outside of the run (and coop if it has no floorand is outside the run) to keep diggers out, this is as simple as one side of some 18 to 24 inch wide wire to the base of the run panel and letting it lay flat on the ground.
For a start up coop, why not find a kid's playhouse, coop, or small building on Craigslist and modify it to meet your needs. That keeps the cost down and allows you to adapt and personalize it to you. Have fun with your birds