I've got two 750 Gb disks that are set to a RAID0 in the bios. My OS (Kubuntu 8.04) sees them in /dev/mapper:

dpich@dpich-LINK:~$ ls /dev/mapper
control nvidia_fjcbehbb
dpich@dpich-LINK:~$

I want to format and mount nvidia_fjcbehbb using NTFS. I have 1.1 Tb of goodies in NTFS on an external hard drive that I have to keep in NTFS so a second location will still be able to read my external hard drive. So I want to format, mount, and have this RAID0 drive show up every time after a reboot.

I've tried mounting the file system with various gui tools, making the file system msdos and other formats, and attempting to partition with gparted. I have yet to make this work.

Any friendly advise on how to do this?

You should be able to partition and mkntfs it like any other device.