Spec Help with Home Fileserver Upgrade

[Valo]

I'm needing to upgrade my home fileserver/download box as I'm running out of hd space .

Spec

1Ghz P3 (Passive Cooling)
512 MB RAM
Intel Motherboard (ide)

2x 60GB Maxtor HD - 1x System Disk - 1x Storage(ditch)
1x 160GB Maxtor HD - Storage(possibly ditch)

I'm wanting some serious storage with easy expandabity but runs quitely...is SATA worth the investment?
I'm also needing a new case which has been made for silence, as it's in my study and the existing case is cheap and vibrates... I was thinking of the Antec Sonata II views?

BUDGET = £300

Options Please!

Budget

 

[Valo]

Cheers for the responces guys..... I've sorted what i'm going to get with the case and the raid card, however i really want to raid 5, three 500GB disks to give me a 1TB of usable storage with redundancy.

So I'm going to have to wait until the price of those 500gb disks come down a bit

What do you think?