they are definately 6x8 all the way around. they fit in perfectly and is a pretty easy job to do. the rms rating of amps is the average power that the amp (head unit) will put on constantly. the max rating is like the label, max output at one instant. most places that do installs will install products that aren't bought there, they may charge more though. car audio really isn't that complicated at the basic level. you don't sound like you are planning on getting into anything too complicated. i think you'll find most your answers here.
