RE: Need to Know PS2 Version –
For the Modchip I would go with matrix infinity or a crystal chip. The HDD can be used for games. You need a Maxtor or Seagate 120 GB because they fit on the Network Adaptor with no mods. The Crystal Chip has a bootmanager which is like a dashboard. The modchip allows you to play import games and backups or maybe some 3rd party apps on the memory card or hdd. You do need some pretty good soldering skills in order to do this which you can get an installer like http://www.steelcityelectronics.com. I hope this helps.
Edit: I hear that the crystal chips need a hacked firmware for backups. Please correct me if wrong .
scph-50001/n v9 matrix infinity fw: 1.91
AMD Opteron 165 Powered!
Burner: NEC ND-3550 v1.Y6 RPC1
Next Consoles: PS3 60 GB and PSP Entertainment Pack