What amp do i need for these car speakers?

Im getting 2 80 watt rms alpine 6 1/2" speakers for the front doors in my 2004 honda accord coupe ex (with 6 cd changer) and 2 6x9" 85 watt rms alpine speakers in the back. I cant afford a sub yet. So for these 4 speakers, but would be the best amp to get? How many watts? Do I even need an amp with this set up?