Audio Systems: Connecting Carradio/CD player to 120 volts, house speakers, regulated power supply

Question
Assuming I need a transformer to step down to 12-14 volts... what type do I need?  how many AMPs?
How do I install it?  
Where can I buy the alternator?  
Are there any drawbacks to doing this?  
Can I run regular house speakers off the car radio?

Answer
go to radio shack and get a 3-5 amp REGULATED power supply. anything else will hum real badly. you can use home speakers, just be wary of volume settings, you should be able to notice when it's too loud, it will start breaking up. other than that, it should serve you well.