IR temps at a distance

I'm currently trying to get IR temperature readings from my wood stove. I would really prefer this over a thermocouple. However, while I have been able to find sensors that can read temperatures high enough (750-800 degrees F) the field of view seems to be a problem. If my understanding is correct it would be reading way too large of an area at the 5-6' away where I would have to place the sensor. Does anyone know if there is a way to narrow the field of view or if there are sensors capable of this?

The MLX90614 family includes members with a narrow field of view (12 degrees or so).

Some of those sensors such as the MLX90614-DCI are almost perfect except that they say the upper limit is 380 Celsius and I need 420-430. Are the sensors incapable of reading temperatures outside that range or is the accuracy just horrible?

How about something like this:

I found it MUCH cheaper on ebay but does anyone see any reason this wouldn't work?

I found it MUCH cheaper on ebay but does anyone see any reason this wouldn't work?

Cheap electronics on eBay are very often out-of-spec, or counterfeit, or completely nonfunctional. Sometimes you don't even get "what you pay for".