We bought some new bathroom scales when both my DH and I decided to do the 5:2 diet and needed more accurate scales than our 30 year old ones.
We bough the Salter MiBody digital scales which, in addition to you weight, works out your BMI and does all sorts of other bits and pieces which seems to be a bit over the top. Big problem is that the display is so dim that it is too difficult to read easily. We changed the battery, thinking that must be the problem - no difference, we complained to Salter and they told us to take it back to the supplier (bought online and they refused to acknowledge our emails so I've given up). Only advantage with these scales is that you can transfer all the measurements via USB to your computer so you can have a graph showing your progress.
My advice would be to look at Amazon and read the reviews there carefully