ok, to start off. i know absolutly nothing at all about car audio. nothing. but i love music, and want my car to sound good. i have a 1996 nissan maxima. i have had lots of problems. and lots of mixed information, so help would be appreciated.

i just got my car and im trying to put some door speakers in. because it sounds like shit now, and i want the quality of my music to sound good. im not looking for 'a beat'. just quality right now. when i went to best buy the guy said aftermarket head units (which i have) only push 7 (im not sure what it pushed, but it was 7) and that good speakers can have anywhere from 60-110 rms (i think?) pushed out of them. so that if i put door speakers in i should probably get a 4 channel amp to power it... well then i told my friend what he said. and he said that the guy was full of shit, and that my head unit (an older model panasonic) should be able to power most, if not all speakers i get just fine. so that is my first question, if i just want quality, and only want door speakers, do i need an amp to power it?

second question. when i went to best buy they said i have 6 1/2's all around. when i called crutchfield they said the same thing. when i went to best buy they said i have 4x6's up front and 6x9's in the rear. when i went to the auto and sound store they guy who looked at my speakers said 4x6 up front and 6x9 in the rear. now, i am inclined to believe the guy at the auto and sound store because he actually looked at them and told me what they were. but i have no idea myself, and got a lot of mixed answers.

so, any help? im sure these are pretty easy questions to answer, but like i said. i know absolutley nothing at all about car audio. what so ever. nothing.