We tried Kingdoms and Towny in the past (I think). Neither of them were that great, and had flaws in certain areas.
You can easily utilize GriefPrevention to create town plots, though. Use the command
/subdivideclaims when equipped with your golden shovel. Right click the ground to create a sub-claim (plot) and then, just
/trust specific members in the plot area.
If you want an example of how it works, take a stick and have a look for yourself at
/warp Westwood. <object class="emojione" data="
https://resources.enjin.com/1489581540/themes/core/images/emojione/svg/1f642.svg?0" type="image/svg+xml" standby=":)">:)</object>