Fiat Punto Convertable Speaker upgrades

Hi,

I have a Fiat punto Mk1 Convertible and want to upgrade the full system. I have a Kenwood CD/Mp3 Head Unit already and want help chosing the right size speakers as the ones at the back are a funny shape and want the front ones to be flush. They isnt much room in the front holes as i tried fitting some speakers before and they stick out and dont fit correctly.

If anyone can help with sizes and recommended speakers as they is 2 channel 4 channel and loads of different types :S

Cheers