I agree with Nissan_MasterTech. Why would you want to risk having the waterpump fail? Replacing it takes so much time and effort, it's just not worth it. On the other hand, I use Nissan parts for almost every job. I don't think you can beat the quality and reliability of Nissan parts.
There are one or two exceptions. For instance, for batteries, I use DieHard. And there are some parts that Nissan does not offer. As an example, on my 2003, I found that Nissan did not offer U-Joints. I bought Spicer, but in the end, I just decided to buy the whole driveshaft and replace it.
But in general, I prefer to buy everything from Nissan.