Well If you just want to play backups the duo2SE might be the best way. Trying to get DNAS backups online is not allowed here. Its only 17-21 wires for the duo2 SE and it can be found for less than 20 USD so its a good solution. It doesnt have the memory card manager or flash upgrades. The infinity and crystal are the best choices if you want a solution that is flash upgradeable. The crystal chip needs a backup enabled firmware which you want the latest version. Do a google search and you can find it. The infinity chip has the firmwares on their website. They are both good chips. Try to get the ones that can suit your needs. If you want hdloader on the MC both the infinity and crystal can do it. It would be nice to identify your console version. I hope this helps for you.
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