1st generation speaker upgrade

Have a little extra money and want to upgrade my speakers on my 01 dbl cab but I don't know much about audio and have a few questions. I don't want a sub or amp at this point. My plan is to mount 6x8 pioneer 3-way speakers in the front doors and a new head unit.
1. What is the difference in a 3 way vs 4way speaker?
2.When the pioneer speakers say 240watt 40rms is that per speaker of for the pair?
3.Do I want to disconnect the tweeters in the front doors?
4. Is it worth is to replace the rear speakers? Do they need to be a different kind without tweeters?
5. Most of the head units I see say 50watt x 4 channel. Will a more expensive head unit give better sound or just more features?

 

1. 3-way = woofer, midrange, tweeter vs 4-way = woofer, midrange, tweeter & supertweeter.

2. Per speaker.

3. If I remember correctly w/o the stock woofer the tweeters won't work so either or is fine.

4. Most people either fade out the rear or disconnect it. I like to fill mine so I have rear speakers. In fact components. A set of coax or 2-way...woofer and tweeter is sufficient.

5. Yes and no...better sound equates to tuning it to your needs. 50 x 4 only ='s like 20+ to the speaker RMS wise.

My suggestions are but not limited to...first listening to speakers yourself because everyone has different taste. Your ears arent the same as mine so I can't say get these speakers. Don't buy blind...listen to the first. If you like them, buy them. Secondly, round speakers > oval. Lastly, I suggest a nice set of components up front, and coax in the rear. Then later down the line you can add an external amp to them.

 

Do you know of the Mid mod for the factory deck? If not, it makes a hell of a difference in the sound quality.