Inspired by the 10 gallon drum available from Oneida, I bought a 5 gallon drum from Amazon because the 5 gallon size would fit more easily into my enclosure and 5 gallons was sufficient for my needs when using the ClearVue supplied bucket. ([ame="http://www.amazon.com/gp/product/B006P5RJ4E/ref=oh_details_o00_s00_i00"]SKOLNIK Carbon Steel Open Head Drum, 5 gallons, Bolt Ring, 0.9mm Body Gauge (Pack of 1): Amazon.com: Industrial & Scientific[/ame])
I was concerned that I would have trouble cutting the holes for the cyclone and its mounting bolts in the steel lid but found it quite easy with my small router. I drilled 3 holes with my drill press to secure the drum lid to some sacrifical MDF mounted on my table. I used the machine to precisely locate and create the holes to mount the cyclone. I used those holes to further secure the drum lid to the MDF and then cut the 6.1" hole for the cyclone.
Photos below show the lid as it was being cut. The last photo shows the ClearVue cyclone mounted on the bucket in my router's enclosure. (I now need to clean up the vacuum hoses.)
This steel drum gives a much more positive seal than the one I got with the bucket. I use a 15/16" socket that I drive with my battery powered hand drill so it is very easy to open and close the steel drum.