This is the one I use, it counterbalances the weight of a bowl or container so I can accurately weigh animals up to 5000 grams. I weigh my 4000 gram animals on it and it gives me a number within accuracy of a gram. One of my females I just weight at 3458 grams.
It all comes down to preference and what kind of scale you want to be honest. Some will be more accurate then others. I on the other hand went with the proven(my weigh 7000).