Will you be driving the car most of the times ???
Then go to Haroon Radio or any other big shop. Ask for 5" component speakers ... get them fit in the front doors of the car.
Add a subwoofer in the back ...
And then get a 4 channel amplifier.
I visited Haroon yesterday to get a deck (bought an Alpine CD-9546E) ... there were cheap component speakers available ... around 5000.