I installed 4 valves on mine originally and have since removed all but one and I have thought about removing that one too. When you put a 3/4 valve on the UDS, the opening is reduced to 1/2 and really does not have the right draw IMHO. I now contraol the opening with cheap (Free) magnets I find from the Pizza joints or dentist office.
Buy a Step drill bit, trust me on this. Harbor Frieght has a two pack for about 25 bucks (Lowes it will run 50). Makes cutting the holes so much easier and cuts cleaner.
two (2) 22 in weber grates is what I used, one holds the Basket on Mine and the other for the food grate. And since I have no welder or welding skill, I used the Stainless Shaker Basket bolted to one of the grates with Stainless Washers and bolts.
I used 2 inch stainless screws , lock washers and nuts to fasten my shelf. 4 corner idea. Eight holes on the lid for the draw. and a thermo. I used the Tel True 300 with a 4 inch stem. I have a couple here, as I was planning on building another couple drums that I have not got around too. I would not worry about a thermo at the lid, the stem will poke into the product. Instead get a Thermo you can place at grate level, so you know what that temp is.
This is what it looked like after I was done. It took me about 2 hours the first time