The OEM fogs are pretty easy to add. I did that with my Legacy.
When i got my WRX, i had a choice between the base and premium all weather package.
Trust me, go ahead and get the premium. You get: sunroof, fogs, heated seats & mirrors IIRC.
If you want the HID's - go for the Limited.
*this was my experience when shopping for a 2012... The audio can be easily upgraded (check the audio forum for ideas).