It depends on your budget. I would go with either crystal chip or matrix infinity. The crystal chip needs a hacked firwmare to play backups which is on this forum by the search function. The infinity has the backup function and it's on their website. You will need to flash it once you install it. I don't know much on o2 mod. The super *** 3.3 is a clone of another chip. The matrix homebrew is compatible with the discs. I hope this helps.
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