I use a large terra cotta flower pot tray with about an inch of sand for my diffuser that is lined and wrapped with foil to catch the drippings and for easy clean up afterwards. I only use the diffuser for briskets and ribs to keep the hot direct heat from burning the outside of my meats. It uses a little more fuel, but has not been a problem. The heat is a lot more stable at the grill level once I get it settled in, which takes about 20 minutes once I get the meat on.
My briskets have been much better since I installed the diffuser. My drum came with a removable lid with the ring strap included. Bought it from a place that re-conditions drums, and paid an extra $10 for the lid and ring. I used three U bolts for mounting my lower grate about 6 inches above my fire basket, which allows me to cook steaks etc over direct heat when needed, therefore extending the use of my drum. My main grate is mounted the same way for easy removal.
Webber 22 1/2 OTG Gold, UDS, rusted out chimney, Red Lavatools Thermowand, Maverick ET 732, 1950 model wife. Walking cane to help me get around.