You may want to get two scales. One for weighing the grain and one for more precise measurements such as with the hops. The grain scale need not be a precision digital model. Most any kitchen type spring scale would be plenty good enough. A lot of my friends have the Escali digital scale linked above and they work well for them. The price is also very good on the Escali scales.
That's what I use for grain and hops. But I just bought a jewelry scale to measure out mineral additions( it goes down to .01gram). I will be using that for hops as well.