The difference between ASUS models is usually the CPU and GPU options.
In this case JK comes with 850M GPU, JM comes with 860M GPU and JW comes with the best of the three - the GeForce 960M GPU. The performance gains for this model are considerable.
The difference in CPUs is not large at all. The top model JW only comes with a 100MHz faster CPU, but it IS objectively better than the rest.
So G551JW has the potential to be the best, because it has the best non-upgradeable components - CPU and GPU. Storage (such as harddrives and SSDs) and memory amount ARE upgradeable and therefore are what you will see as being different between different units of the same G551JW model, for example.
It is advisable to purchase the best model out of the 3 in terms of CPU and GPU, because even if you have lower-end storage and memory options, these can be exchanged in the future, whereas CPU and GPU cannot, as I mentioned above.
If you're looking for shopping advice, give us some offers that are available to you and we'll look at them for you.
