I think I'd support the suggestion to use Warnings and related Warning actions for this purpose. It will do exactly what you want, quickly, easily, and without any need for add-ons. You can EITHER
- have different point scores to create bans for different durations
eg
10pts = 1 week
20pts = 2 weeks
30pts = 1 month
40pts = permanent
(or whatever scheme suits)
OR
have a single action related to a point score, and allow the warning duration itself to be altered when given
eg
10pts = ban
If the points have a 1 week duration, then the ban is for a week.
etc....