Adding Thermocouple to Royal #5 Antique Roaster

[valleyislechoco]

I recently purchased a restored Royal #5 coffee roaster to use for roasting cocoa beans. I am trying to get together the correct thermocouple components to get good temperature readings. I bought a digital readout and a 24" probe. It seems I may also need a wire or connector to give the readout some more distance from the roaster? I'm new to this. Just posting to see if I can get any advice from experienced folks. Any advice is appreciated. Many thanks!