Can someone recommend me a dual-band omni antenna for connection to a Cisco 3600? For use indoors.
I have found this:
But it seems a bit overkill for what I need. All I want is a small profile indoor antenna I can connect to the AP.
I require the antenna so that the AP can be mounted vertically with the antenna sticking out the top so as to create the correct coverage pattern
This document link you've posted is already OUTDATED. All the antenna's in this PDF are valid up to the AP1250. The antenna required for the 3600, as what is stated by the OP, is totally different.
Antennas for the newer generation of Cisco APs which are dual-band radios, go here.