Roost: 2X4 board with wide side turned up. About 8" of roost per chicken. 30 chickens = 20'.
Board: Just, that, something flat on the ground below the roost, like scraps of plywood. Some cover it with some sort of vinyl. Some build a holder for it. Some buy some sort of plastic tray, or use lids from large plastic bins. Might use sections of cardboard boxes and toss when they get nasty. Whatever is around. Scrape it off in the AM to minimize droppings left in coop. Dustpan works well to do this.
Or just fork out the top layer of litter in the AM.