Water pump opinions

Need opinions on replacement water pumps.
In the process of a complete rebuild on my 5.0 roller block. Looking at replacing the water pump just to be on the safe side.
Motor is set up with the standard rotation water pump. Cast iron or aluminum are does it really matter. Trying to go with a new pump.

I milled this over for sometime before I purchased a GMB aluminum unit from Rockauto. Way lighter than the OEM unit and it appeared to be a quality part. Lots of good reviews on GMB units on the web prior to my purchase.

https://www.rockauto.com/en/moreinfo.php?pk=3096312&cc=1121678&pt=2208&jsn=947

I was looking at that one also. It is a direct replacement for the cast iron pump?

It was for my 351 Windsor.