Nest boxes - number of chickens is irrelevant - they all want to use one or two of the boxes and not the others - until one day they decide it is box #6 that is most appealing - or that bush next to your house or...... I had 12 hens at one time and they typically all laid eggs in one box or, if someone just couldn't hold it and there were already three hens in the preferred nest, maybe two boxes.
Perches - the links and recommendations above are good. Given the various sizes of chickens you mentioned, you may want a lower perch or a step up to the perch. Otherwise, 12-18' high seems good. My hens prefer natural limbs as roosts - roundish, about 2-3' in diameter. Lots of folks use 2x4s. You might also want to place some extra roosts in the open section (in corners or along walls) for they to use during the day.
The plan looks terrific so far.
Perches - the links and recommendations above are good. Given the various sizes of chickens you mentioned, you may want a lower perch or a step up to the perch. Otherwise, 12-18' high seems good. My hens prefer natural limbs as roosts - roundish, about 2-3' in diameter. Lots of folks use 2x4s. You might also want to place some extra roosts in the open section (in corners or along walls) for they to use during the day.
The plan looks terrific so far.