Another amp question

[jarrett at rpa.net (Jim Jarrett)]

If I'm looking at a head unit that puts out between 50- 52 watts, is  
it worth it to hook up an amplifier that does 80 watts?

And if it's a 2-channel amp, then I can only hook up 2 speakers, right?

The current setup is that I have a stock radio in the car.  The rear  
speakers have been replaced; I don't know about the fronts.  I am  
guessing not, cus they sound like crap.  I will probably replace them.