weaste mate, i knock nails in wood and slap bricks on top of each other, thats just gone right over my head, got the one about amazon 20GB, but putting a new hard drive in , is it easy, i realy am a bit clueless with this stuff
Very simple. Some people have a problem with the screw and strip the head, but I expect you would have no problem.
The only problem with importing one is that if something did break with it, then it would be a pain in the arse to send it back.
The 20GB also does not have wireless in the box, but the cheapest US 60GBs I can find are around $700 - I don't think that it would be worth it. The US 80GBs are also around the same price, and they only have 50% hardware backwards compatibility.
I'll try to list the different models and features off my head (without going into strange Jap models) - HDD size is obvious.
US/JAP 20GB (Launch model) - 4 USB ports, no wireless, no card readers, PS2 in the box. (No longer in production)
US/JAP 60GB (Launch model) - 4 USB ports, wireless, card readers, PS2 in the box. (No longer in production)
Europe 60GB (Launch model) - 4 USB ports, wireless, card readers, PS2 graphics chip in the box, PS2 central processor emulated on the Cell. (No longer in production)
US/JAP 80GB - 4 USB ports, wireless, card readers, PS2 graphics chip in the box, PS2 central processor emulated on the Cell.
All of the models above have their 2 main processors made at 90nm. Later models - the Europe and US/JAP 40GB and maybe some US/JAP 80GB now coming out are on 65nm (Sony is slowly moving towards 45nm). This means that they produce less heat (are much cooler, and quieter because less fan speed is required) and also consume less power. They also have better Bluetooth and Wi-Fi range.
US/JAP/Europe 40GB - 2 USB ports, wireless, no card readers, no PS2 backwards compatibility - possible in the future in software but also possible that it never happens.