Regarding IDE drives.
My backup clone is on a IDE drive and boots fine, also the dvd drive I sometimes connect is IDE.
I don't use any special kexts. It's just a hassle to get the little jumpers right on the drives, the master/slave thing. And then the connector on the IDE cable matters too, middle or end. One time I couldn't get it to work no matter what I did, but then I discovered that a cable had got lose at the molex connector, so no power...