You need a scale with accurcy of +- 1 gram only, max capacity of 5 kg--depending on how large your batches are. Only "feature" you need is the tare button, which is standard on every scale.
I perfer the Matfer alcohol filled thermometers. Yes there are many good electronic ones available. Remember the probe on the electronic ones are pencil-point small, the bulb on the manual is much larger. Taking the temp. of say, a caramel/toffee is a matter of opinion, as you will get diffeent readings depending on where the probe is.. The smaller the probe, th more different readings you get. Electronic probes wear out pretty quickly, the alcohol thermomters don't--unless you take the thermometer out of it's "cage" and drop it....
Hope this helps