Looking for nonexistant PA sol'n

[Ottoman]

I am also a newbie at modding my car. I just bought a 2000 4runner several months ago and have installed a few items, one of which is a CB radio. Other than speaking to other vehicles with CB's I would like to speak to people outside my car without CB's using a PA system. CB radios put out very little power for a PA, so I am looking to amplify the signal. The speaker I am looking at is 11 ohms resistance which will burn out most consumer amps on the market because they are rated for 2 or 4 ohms. My question finally... does anyone know of an amplifier that will boost my signal from 4W to about 100W AND handle the 11 ohms? OR how do people get strong signals from their PA's? Any advice will help, so please don't be shy.
Thanks.