Wanting to install a head unit in my Corolla S, how would i go about doin so?

[RollaWitCorolla]

I just got my 06 Corolla S last week so everything is just stock. I am having withdrawls from the lack of my subwoofer. I was wondering what i need to buy to install the head unit. I notice most if not all people who have a head unit have a head unit bay thing. where could i get one??

I was also wondering is there was any chance that the stock stereo system could power subs alongside with an amp?

also, how do i get behind the stereo system? do i hafta take apart everything to get back there???