@Darrin
+1. Nearly exactly what I was thinking.
+2
I remember well weighing up the choice between a sidecar drive and an internal 2.5 inch with a third of the capacity (or three times the price). Then I read a magazine article in which some clever bugger had squeezed a 3.5 inch drive into his A1200 internals (maybe hacked would be more accurate than squeezed XD ). Great idea, thought I..... If only I could do that without voiding my warranty.
In the end the choice was made for me by someone giving me a 20Mb 2.5" drive.