Hi,
I have made several bin cages now from different suppliers, the ones I recommend can be bought from Viking Direct and are 64 litre, they are 710 mm long. I just bought 6 from their today, ordered at 11.00 and received at 15.00. The plastic is thick, probably about 4mm and the easiest way to cut the shapes is with a craft iron, its like a soldering iron but even with this it takes a hour or so. Once the shapes are cut out I cut a piece of mesh approx 1" larger on each side, I then place this over the cutout and mark where to drill, I usually do the 4 corners first. Then I place bolts through and mark and drill rest of holes. The drill size I use is 6.5 and the nuts and bolts are bought from Wickes, legnth 20mm which was the smallest length I could find.
Here is a finished one...
I have also added a shelf by using the plastic I cutout from the lid, cut to the width of the cage and placed on 4 wooden legs of approx. 6" high. To attach I drilled hole through each corner of plastic and used screw to attach to legs.