You can buy a Brute storage tote for $20 at Lowes and make your own. Now I just have to figure out how to secure it from sliding around inside the box.
Nice job! Maybe a big ziptie looped thru a hole in the side or front, combined with a small bungee? A dump-salvaged ice chest also makes a decent starting place for a saw box.
Is that a 6100? I'd've thought a 6100 would fit in a powerbox or cheap equivalent.
You should be able to cram a few more things in there to keep it from sliding around. buncha wedges, small tupperware-like sandwich snap box with extra chains, etc.
You could also get some high density foam or something like it about 2" thick to fill the bottom of the box. Trace the saw base on it and cut that part out so the saw fits into the foam.