LaCie Big Disk Extreme case... need advice on drives to put inside

[spriter]

Hey guys,

I've a LaCie Big Disk Extreme case here and I'm looking for advice on what drives I can put inside and the configuration.

1. Do both drives have to be the same size (exact?) and from the same manufacturer?
2. What jumper settings should I use on each?
3. Will I be forced to format and have both separate drives be seen as one (RAID)?

I've got two 250GB external USB drives which I'd like to put inside and run from the much faster Firewire connection but am concerned I might wipe the drives.

Any advice is greatly appreciated.

Thanks.