Best kind of meat thermometer
Definitely you would prefer having the probe instead of the instant, as you want to avoid opening and closing the oven.
I checked out America's Test Kitchen website to see what they recommended, and even their recommends were with reservations. They found the digital probes to be either inaccurate or hard to use. But their recommends were: Thermo Works Original Cooking Thermometer ($19.00), Polder Classic Thermometer ($24.99) and a couple of Mavericks for the twenty dollar range. I see somebody recommended the Pyrex, and that's not on the list at all, so maybe it's worth checking out.