Buckets are one of my favorite tools! So useful for so many things. I can't get or carry the big log stumps
@RoyalChick has & are great. But an upside-down bucket firmly set into the litter / ground works well. It's light and you can make easy changes in layout. Also, they like to drum on it.
I don't have enough "under" places. I want to make another place or two like under their veranda & coop - a low card table would be ideal.
Cinder blocks: places sell different kinds, different sizes/materials/weights and with differently-sized & -shaped holes. I had no idea of the range! Also, ensure the blocks won't tip over however you use them. Building a base of them together on their sides would work. Here, placed singly on end, I sweep the bouncy litter away and make sure they are firmly on a paver underneath.
Perry will have to go through her integration, just try to ensure there is enough space available for the number of chickens, and always somewhere to escape to and from, whether high or low. Usually the bouts of intimidation and attacks are short-lived. Just make sure Albert & Whiskey aren't so serious and persistent as to be really wounding her. They have the most to lose if she decides to be a social climber, they want to make sure she doesn't pass them in pecking order. Maybe Perry does have spunk and drive and sees them as equals since they could be pretty close in age. They'll have to work it out.