Setting up sound system in my 2003 Dodge Durango.?

I don't know very much about cars or sound systems. I was planning on getting these sub-woofers http://www.ecost.com/detail.aspx?edp=40768276 and this amp http://www.ecost.com/detail.aspx?edp=40768591 for my Durango. I was wondering if anyone knows if this is all I need and also if they're compatible with each other and with my Durango. Also I was wondering if anyone knows anything about the company Pyramid, because I don't want to be stuck with bad stuff.