Last I heard the ones you used with the ear were the "best" as in most accurate. This is of course if you can get it to work, which I never seemed to get the hang of the darn thing.
With most digitals, make sure you place it fairly far back beneath the tongue and hold it steady until it beeps will give you a fairly accurate reading. If accuracy is the key, I'd see if I could purchase an old fashioned mercury type (it's not mercury anymore), learn to read one if you don't know how (it's really not hard to do) and use that instead. Downfall to it is that it will take 5 mins each time for an accurate reading.
Just my opinion. I grew up with the old fashioned type, got adept with using them.........don't mind digital but still prefer the old type to be honest.
Maybe the pharmacist could help or the doctor office?