Just get the Japan because its the cheapest! The PS3 can play any region games anyway. Yun nga lang Japan is 110V and so is the US. Yung Asian version 220V pero mas mahal. I would just get the Japan (pinaka mura) tapos just buy a AVR and plug it into the 110V. You can buy HDMI cables sa CD-R king really cheap, tapos use that to plug your PS3 to your HDTV.

As for storage, maskin ano. Ako I have 40GB I am fine with it. Of course the more the better, meanse more space for installations and storage.