I very rarely use antiair for anything (its practically useless, much like interceptors, hehe).
My normal coastal garrison division is 2xgar and 1 or 2 art. Its not a strong division per se, but will chew up anything trying to invade by sea (armor invading by sea gets hit by so big penalties that i prefer a second art over an at brigade). Also, if you have the IC to spare, building coastal fortifications helps a lot.
For regular garrison divisions, i never use garrison brigades, they are far too slow (1 km/h). Same goes for police brigades, they dont surpress anything anyway, so are useless in their intended role. I use whatever i have available really, infantry, cavalry, light armor, motorised, etc.
Infantry is fairly slow (4 km/h), but cavalry is only 1 km/h faster, which makes them useless as fast counter units (compared to vanilla infantry). Light armor and motorised have a speed of 10 km/h, but are far too costly to use on a grand scale as revolt supressors, so its a bit of a juggle of what i have available.
