Ford holds a tight spec on the people that are rebuilding the calipers sold as Motorcraft. Your not going to be able to get brand new calipers for a 2001 so If it was me I would get the Motorcrafts.
The problem you always have with rebuilt calipers is were the rubber components moulded to the exact sizes, were the rubber compound exactly the same as OE or was a generic version used, how well did the company clean the dust boot and seal grooves in the caliper body, and how well were the phenolic pistons made, as in the resin used and the cure of the parts. In the last half dozen years on the forums were seen a higher rate of rebuilt calipers' pistons hanging up, which I suspect may be a swell and growth issue with the phenolic pistons more then excessive diameter when machined.
The other thing I would recommend, and you can only economically do this over the counter, is to look at the caliper your buying and see how rust pitted it looks. While a company can clean all the oxide off the surfaces, a caliper that has seen a high share of road deicers will have deep pits, and while those pits on the exterior do not have much effect, typically they are also present within the dust boot groove, and deep pitting there will not allow the new boots to seal as well, allowing more moisture to enter under the boot.
The problem you always have with rebuilt calipers is were the rubber components moulded to the exact sizes, were the rubber compound exactly the same as OE or was a generic version used, how well did the company clean the dust boot and seal grooves in the caliper body, and how well were the phenolic pistons made, as in the resin used and the cure of the parts. In the last half dozen years on the forums were seen a higher rate of rebuilt calipers' pistons hanging up, which I suspect may be a swell and growth issue with the phenolic pistons more then excessive diameter when machined.
The other thing I would recommend, and you can only economically do this over the counter, is to look at the caliper your buying and see how rust pitted it looks. While a company can clean all the oxide off the surfaces, a caliper that has seen a high share of road deicers will have deep pits, and while those pits on the exterior do not have much effect, typically they are also present within the dust boot groove, and deep pitting there will not allow the new boots to seal as well, allowing more moisture to enter under the boot.