Let's deal with one problem at a time

First, you have to set up an array (before any Windows come into play or DOS)
Once that is done, upon the reboot go into bios and where you have "Boot Device Sequence", you have to have:
first device: floppy
second device: ATA100 (or whichever one you've got) RAID
third device......
BTW, I hope you know it, but I'll say it again - you'd better have the same model drives, or else...

Before you scrap your current system, use it to make the raid controller driver floppy disk. YOU WILL NEED IT!!!
Well, the rest is easy...
Load the first floppy os loader floppy and reboot.
As soon as the "blue screen of life" shows up, at the bottom it will say: "If you have raid controller and have driver for it click F6" (do not quote me on the exact frase) DO CLICK IT RIGHT AWAY!!!, since you are not given much time by MS to snooze

If you miss it, you'll have to reboot again
After floppy 2 is done loading it's stuff, the os loader will ask you to click S if you have that aforementioned floppy, so click S, insert the array controller floppy, then enter, then choose the appropriate controller if it's got more drivers than one.
.....
As soon as you are done loading the 4th floppy, you'll be asked if you want to remove the existing partition and then reformat the drive, at which point you will do it, so you don't have to warry about it before hand

Good luck!