Carter is good, especially if the assembly is in good shape and you can just swap out the pump itself rather than buying an entire assembly for twice the price. If you just replace the pump, be sure to replace the old strainer with a new one as well.
However, the stock pump assemblies are often are made of mild steel rather than stainless, and so are rusting and sometimes falling apart by the time they are due to be replaced, in which case you don't really have a choice and have to buy an assembly with the pump.
I suggest going to or calling NAPA and pricing both the pump and a complete assembly, their pump assemblies seem to be (or used to be if they aren't anymore) Carters that are just boxed as NAPA brand. Their pumps also used to carry a lifetime warranty, but NAPA stuff doesn't have much of a warranty anymore, so that may no longer be the case.