sounds cool, but pricey
if you really want to burn on the cheap, dollar for dollar, the emac with superdrive is the better and more practical option in the long run...plus you would have the g4 with the emac which should speed things up...and time is money
but if you love your ibook and you want it as your sole machine, then get the superdrive
it may be a short matter of time before apple has a superdrive option for the ibook...i don't think they would like to see this company make all the money with this concept