It was actually fairly simple (direct Amazon links):

ELECROW Raspberry Pi Touchscreen Monitor 5 inch HDMI Screen Display 800x480

Cable Matters 2-Pack Ultra Thin HDMI Cable 3 ft

90 Degree Right Angle Micro USB Male to 5 Pin Motherboard

I cut the top two tabs off the HDMI screen with side cutters and it was a perfect height to wedge into the basement window without any connectors. In hindsight I did not need the 90 degree right angle on the micro USB, but it still worked. I am using AIDA64 with one of the 800x480 sensor panels I found on this forum thread. I have tweaked it to use the values for my machine and that was it.