I have never seen a indoor or out door catalog shoot that did not involve augmented light. It has nothing to do with being incompetent for needing it, it is about getting what the art director expects. Hundreds of final images including in the catalog will have a set style so there is consistency between catalog items. Please forward the contact information for the pro commercial photographers you know who do not use augmented light for catalog....maybe they have some secret the thousands of fashion shooters don't know about. Telling the OP he does not need lighting for his task has the danger that he might believe you and waste his whole project schedule and money.
I have also never seen a cover shot for a major publication done without augmented light. Are you forgetting what the OP's requirements are, what is trying to do? With all natural like no two images will have the same lighting let alone hundreds of catalog items. I was involved with dozens of record album cover shoots for major label releases and even those with the plan to appear natural, outdoors, were anything but all natural.
No question the D700 was a fine camera, but why spend more and get less solid files? It does not make sense, everything since that era has eclipsed the image quality of the D700 in DR, color depth, color fidelity, shadow recovery, resolution, data transfer rates, improvements in tethering(used in most commercial studio photography) and more. My suggestion for crop is based on the needs of the task plus budget of $2000. All quality Fx lenses are going to kill that budget.
Yes, repairability is an important deciding point for any business that will depend on a tool and physical asset. Why argue points that are just common sense and standard practice for a business? If you have had no repair issues, that is good for you, but it is not the norm, you have been lucky.
It appears you want to argue about your preferences and not the OP's needs, budget and task solution. By using standard industry practice, of using good light, both the high cost of a top camera and top lenses is avoided. Great light trumps cameras and lenses for impact on the final result. And $200 in lighting beats the heck out of $2000 for a good fx lens, which with poor light would have to be used wide open, the exact opposite need of a catalog session where all details have to be within the depth of field, and stopped down to at least 5.6 but more likely f/8. These are not portrait sessions where shallow DOF is desired, in this case shooting 1.4 or 2.8 will result in parts of the clothing to be out of focus.
The only reason I am responding is to help prevent the OP who had a sincere question, from being sidetracked into spending more money and not getting the results he needs, for no reason. No one is suggesting you need to use lighting or use budget saving equipment so why try to derail him?