silkie roosts and nest boxes

[sydney13]

so im building my coop and now i have to put in the nest boxes and roosts. ive got a silkie and some other heavy breeds like jersey giant and cohins. the silkie can hardly fly and the highest she evr goes is up my porch steps. so do you think if i put in a ramp to the roost a silkie would go up it?
and i want to stack the nest boxes un top of each other so that one would be at ground level for the silkie. does any one have nest boxes on the floor and use the deep litter system, does the litter cover the nest boxes?