I would be wondering about the infrastructure. For example, what battery would you use? What holds it all while you shove it into your ear? Where do you read out the temperature?
I'm no expert of thermopiles but it looks to me like Arduino / Atmega328 or similar would do the basic job.
You could probably run it off 2 x AA or AAA batteries, the processor can run at a reasonable rate with 3V power.
You probably want to investigate a compact LCD screen to show the temperature, or maybe a couple of 7-segment LEDs, providing you power them off quickly to save power.