There are effectively 3 lens in the Nikon (Nikkor) line:
- Old non-auto focus (< $350)
- Less old, non-VR with auto focus ($350-425)
- New VR ($600 used, $725 new)
For tank shooting (from what I'm told) you don't need AF. And, you'll turn off VR on a tripod, so in theory the oldest lens should be fine. There have been some upgrades over the years to other things, like the number of blades, etc, so there are reasons to buy the newer ones as well. Any should be fine, unless you know why you need/want the features in the newer lenses.