Can someone recommend a good thermometer that can be used for hand-tempering chocolate as well as boiling caramels?
The most highly-recommended instant-read thermometer is the Thermapen from Thermoworks. It's not cheap - about $100 - but people who use it swear by it. There are ones that are far less expensive and I don't know that these others are not good options. You can use a digital probe thermometer for caramels. If budget is an issue, try other Thermoworks options: https://www.thermoworks.com/Pocket-Digital.
If you're going to be table tempering (as opposed to tempering in a bowl) then the mass of chocolate may not be thick enough to use a probe thermometer. In which case an infrared thermometer is a good choice for tempering chocolate - they are not a good choice for caramels. There are a lot of cheap (under $10) infrared thermometers and I would not be comfortable recommending something at that price level. Then again, you don't need to spend $500, either.
Thermoworks does make a hybrid IR/probe thermometer for about $120. Because it's two-handed when using the probe it could be cumbersome in some applications.