If you don't listen to your music real loud, you'll be fine with the stock hu. If you turn your stereo up loud enough to distort the signal, that's when you run risk of damaging speakers and require an amp.

 

What model is your sub?
EDIT:
NM, found it.


Here's an amp that will work:
http://www.onlinecarstereo.com/CarAu...ONX11000D.aspx

I wouldn't run anything that says "Dual" on it.

 

5 channels are the way to go if your running a small to mid size system.

My 5 channel is small enough to fit under my rear bench and has a built in fan that's a god send in the summer.

 

Thought I'd share with you that if your not looking for audiophile quality from the amp the Power Acoustik 5 channel is cheap and will push your speakers. I had an older one in my previous XJ pushing 4 rockford 40rms speakers and a kicker 150 rms single voice coil sub. It wasn't earth shaking but it sounded good for what I wanted and more importantly what I paid. Oh it also comes with a bass **** so you can adjust your bass level from the front seat.

http://www.sonicelectronix.com/item_...-GT5-2500.html

 

Thanks for all your help guys. What do you think about this headunit? I know its an older model but I ask because a friend is offering it for $50.

http://www.crutchfield.com/S-Ey42lHe...DC-MP438U.html

seems like a pretty decent one to me...22W rms x 4, 2.5V preamp

 

Kenwood is good to go for the most part. For 50 bux, get it. 2.5v pre amp isnt much much it'll do, good thing about this radio is that it has front rear and sub channels.

 

My only complaint with the 5-channel that I installed was the size of it - just a bit too big to mount under the rear seat. I had to build a false floor in the cargo area to hide it.

 

Both of those are perfect for your needs and budget.