help needed: gentoo on Promise RAID 20376

[[n00b@localhost]]

I have an MSI K7N2 Delta ILSR with an onboard Promise RAID chip. I have flashed the chip with a hacked BIOS to allow full raid on IDE 3. There are 2 80gig drives striped on this controller. It has been partitioned into a 20gig (bootable, active) partition for windows XP, a 140gig partition for program files and 20gig free space. This is where I want to install gentoo. (I also have two 30gig drives on IDE 1 and 2 for documents and random crap.)

I have tried the full and minimal install cds and cannot get them to recognise the array so my plan is as follows:
Install gentoo on one of my 30gig drives;
Compile the kernel with the promise drivers;
Either copy the installation to the array once it recognises it; reinstall gentoo to the array from the existing installation; or, make the ft3xx.o module and insmod it on one of the install cds.

Has anyone been able to install gentoo in a similar configuration? How did you do it? Does my plan look as if it will work? Which of the above is easiest to do?

Finally, do other distros (Mandrake, Fedora) have facilities available to install on RAID arrays?

Help appreciated

Gary