we have a lot of lightscribe enabled drives at work, ranging from as cheap as we could get to some fairly expensive "brand name" ones in the high end workstations.
I can not see any appreciable difference in the performance for burning or "scribing" the label.... But..... We do only ever use them for fairly bold text labels, which is what they want it for.
Replacing an internal CD drive is something anybody who can change a plug can do.... it really is that easy. you have nothing "computer wise" to do, it's a physical change only, pretty much unplug one plug the other in.
The difference between IDE and SATA visually is so massive that telling the difference isn't hard at all, take the side/top of computer and look at the back of the drive.
Ide will look like
http://www.cablesdirect.com/prodimages/IDEHD-1 _LR.jpg
and SATA
http://attachments.techguy.org/attachments/116 416d1190839928/sata.jpg