[Solved] Advice?

I currently have an optiplex gx520 running WHS 2003 with on an 80GB OS drive and a 1TB storage drive. I am interested in expanding this and have been reading intently on it. I am looking to go up to about 1.8-2TB storage which will all be mirrored via folder duplication. Problem is the box only has 2 SATA ports and 1 IDE port. I am willing to get whatever drives will be necessary to make this work. (Currently I think the 1.5TB have the best $/GB ratio). I realize that the space I want will not be doable with this current setup. So, should I buy a new MB or can I just add in a PCI card to add some SATA ports. I do have a 160GB IDE drive laying around but I read that you want to install the OS on the largest drive. Also with pooling the data goes to the OS drive first, so I'd rather that not be an old 160gb drive.

You should consider archiving old stuff you don't need on external USB hard drives. That way, if you need to suddenly access them, it's easy to do so. I don't see why you need to expand your storage when there are most likely a of media you can "put away" for the time being.