For thermometer holes, I drilled out a replacement car valve stem. Fairly cheep. I have one right below my grate for pit temp, and a second a few inches above my great where I thread a digital remote for my meat temp. Both of those are digital on mine, but pretty sure a turkey thermometer would work fine for the pit temp. I have a mounted thermometer as well, which I just leave attached 24/7.
I used a nipple screwed into my bung hole for my smoke stack on my second UDS. I used a threaded conduit fitting and some metal conduit on my first.