i´d get a nikon d700, it supplements the mfdb more than it replaces it. it has good high iso, fast frame rate, fast autofocus, live view, smaller and it might get 99% of the jobs done should your mfdb fail. you can have zoom lenses, fast primes and some pc lenses for it, 35mm has longer and wider lenses. it would give you more options, a mfdb is not always the right tool for every job.