Kelly, here's some general decisions / tradeoffs. A more precise answer would require additional detailed on the specific shopping center(s) you are working on:
- Do you have dedicated operators who will monitor the cameras and track suspects live? If so, go for PTZs. If not, avoid PTZs and save money. Secondly, if you go for PTZs and use IP, be sure that your combined solution does not have too much latency.
- Do you want the cameras to stand out or blend in? Some centers / locations want their customers not to feel monitored. If so, go for domes / mindomes. Otherwise, as is common in higher crime areas, use bullets.
- Typically, in retail, frame rate is not a major consideration as the actions are not that fast moving (save for cash counting, etc.). Somewhere between 6 and 15fps, depending on the end user's subjective preference and budget constraints on storage should work.
- Answering on resolution abstractly is hard. General recommendations are dependent on width of areas you want covered and how much details you want to capture (i.e. ppf).