We made a chain gear driven 24"*36" tumbler for doing angle and flat stock, , the inside had 4 horizontal plates about 3" high the whole width. Gear reduction box gave us a speed of about 60 rpm. The best media I found was slugs from the ironworker, granite and grindstones just did not last more than a few hours and did not works anywhere as well. 5 hours compared to 30 min....Now as far as the noise, you could hear that baby 2 blocks away in an industrial area!!!!!!
I would line with floor mats screwed to the inside. We often loaded 300 to 500 lbs in that baby, sure made deburring nice. Hope this helps, Paul