What you need really depends on the use cases. How often do you interact with it? The more assumptions you can make, the more often you can go to sleep. What is key for you is lowering the duty cycle and a few other things.
When the WiFi module is asleep, it is not always available for communications (some have a low power polling mode). Going to sleep introduces a delay which in some applications is acceptable and in others (especially human interaction) isn't.
In reality you will need to give a lot more details for you to find a solution, since aside from the hardware, it's really the software you'll need:
1) Support for802.11 g or n need
3) Are you using embedded linux or a simple microcontroller?
4) Do you need WiFi direct or any specific feature of WiFi?
5) How do you do provisioning, which is connecting the device to the AP and accessing it. Sometimes you can type a key (like a smartphone) but in many others you can't. Some devices have better ways of doing this than others.
And many other questions.
Number 3 and number 4 are easy requirements to meet. It's all in the HTTP webserver.
From my experience, you have two widely available solutions, both from TI:
WL1271 which is targeted towards systems with Linux and WinCE. It has a polling mode that lowers the average current to a few mA.
CC3000: This one is targeted towards the Microcontroller market. Putting it to sleep causes it to draw a few microamps of current, but no communications happen there.
Qualcomm and Broadcom also have some WiFi modules but they're harder to get unless you contact them directly.