For such an old server, the drivers are probably already included into the Linux kernel and so they will be included on the installation CDs of practically every modern Linux distribution.
The RAID controller was optional in NetServer LC2000. If it is installed, it should be either NetRAID-3si or NetRAID-1si. Both of these are HP-branded versions of LSI Logic MegaRAID, and are supported in Linux by the "megaraid" driver that has been included in the standard kernel for a long time.
You should also find the configuration utilities and RAID monitoring program. According to this blog post, they should be available on the LSI Logic website:
...but you might need to know the actual LSI Logic hardware model name for the controller to find the downloads, instead of the HP model name. If I recall correctly, the "megaraid" driver will display the LSI Logic model name in the "dmesg" listing when the system starts up and the driver is loaded. (Alternatively, the information might have been available under /proc/driver or /proc/scsi once the driver is loaded.)
