re: Dust collection

Some of the big box stores carry the two grades of metal HVAC ducting (or you could get them to special order with free ship to their store). I spent a lot of time searching, but went ahead with the 6" "thin" stuff for my 2HP cyclone DC. No issues with collapsing when all ports are fully plugged. Long straight runs are just SDR PVC (6").
The thicker metal stuff is what I see commonly sold by the DC suppliers.
Shipping would be a killer with the long box dimensions.