Upgrade HP Proliant ML330 G3 server’s hard disk

Hello all. I have a HP ProML330 G3 server w/Windows 2003 located overseas; and need to find an IT provider to upgrade hard disk space. Not sure what to buy or recommend, but server has a CSB-6 Ultra ATA 100 IDE RAID controller w/(1) 80GB hard drive. HP’s site not very helpful. wondering if you have any suggestions. thanks,