Golf 4 speakers

Hi guys. I’ve been a proud owner of a Golf IV, 1.9 TDI, 110 HP Edition 5-door for 1 month now. The car has the standard BETA Radio and a VW CD deck. Now I would like to have a new radio (preferably blue dot because of the GALA function) and of course also a few speakers in the rear doors. Have read here that you can easily install the front speakers in the rear doors. Only what is nice about speakers for the front? In my Golf 3 I had a Pioneer radio (4×50 watts), Pioneer speaker in the front (2×130 watts) and Pioneer speaker in the shelf (2×180 watts). All this without power amplifier. The sound was absolutely sufficient for me. So from the sound I need something normal-good with which I can hear some loud music. Is there a recommendation for speakers? And if someone has a radio (with GALA function) for recommendation I wouldn’t be angry either. Thank you! Would be really grateful for answers. MfG. LogSeb