Macs can read but not write NTFS, so you may be able to transfer data one time to HFS or FAT32 formatted drives if you want to directly use the data on the Mac. A Firewire external case would be best for transfer.
After copying the data, you could reformat the drive(s)
Alternatively, as you mentioned, you could share the drives to the Mac via a network server. Some NAS units will want to reformat the drive before sharing it -- obviously not the thing you want to do. Most NAS units run on Linux variants (not Windows), and don't use NTFS drives.
THe only way to directly share the data that I know of, without copying or the risk of formatting, is to attach then to a Windows machine and do Windows file sharing from there.