Try searching Amazon for Seville storage cubes or c&c grids.Where would you get the grid cage blocks? Shush don't tell hubby but when we convert the dinning room into a gym i'm going to put the guineas in there with a run so they can have run time whenever they want and i can use the gym in the evenings ( they are used to noise etc with 2 kiddies) x
i just use c+c grids and cable tie them together, then clip the ends to the cage. it's up permanently but can be quickly folded down if needed (house inspection )
The fabric runs look ace. I would worry about them eventually getting stained or smelling over time even with washing