Having a coop two feet tall will make it hard to clean, and there will barely be enough room for them to roost, take my word on this mine is three feet tall.
The general rule of thumb is floorspace per chicken, at 4 square feet per standard bird.
All of your birds should be standard size, so you will need 16 square feet, that could be in any sane arrangement.
8*2
4*4
the plan of 2*5 is 10 square feet and good for 2.5 standard birds or two standards and one bantam.
Here are pictures of my coop and run.
https://www.backyardchickens.com/gallery/album/view/id/6177963/user_id/44847
the coop part is three feet across (wide) counting the nest boxes with external access and three feet tall not counting the stilts, it is 5 feet long. with 10 total 12inch*12inch nest boxes and a central roost bar...
In the end it will depend on how you will use your coop, if they will always have access to a closed run (like mine), you never go on vacation and your weather is perfect year around- you can get away with a smaller coop then 4 square feet per chicken, if you might have to leave them in there due to deep snow or a hurricane warrning or illness or vacation you will want more room then recommended per bird.