Yes, i did change the physically connected disks, that was because my
bios wasnt giving me the option to boot from the secondary channel. So
i wanted to find out if that was a bios restriction or if it was
because the drive didnt have a bootloader. Note, it's the secondary
channel, not a slave drive ( thats irrelevant )

This is not fundamentally hard what I want to do. This is exactly what
linux raid does, and there must be loads of people with setups like
this. You're making it sound like it's worse that it is. ( dont get
me wrong I appreciate the help) The basic question is how do I make a
drive which has an image on it, into a bootable drive?

oh; I dont know where you got the 95% statistic from but thats not why
i'm using raid. I need to protect against drive failure, nothing more.
I'm not even fussed if i have to change drives physically when one
dies, but just as long as I have the image there and ready to go!

does that make sense?