@ mad_man: yes mate. this is all very possible. did it on my NA glanza S conversion & it was superb. take a peek at some of the progress pix.. sorry, no image tags. too lazy..
you'll need to source the parking brake cables too when getting the axle as the drum-type cables don't fit. other than that, all else is compatible. remember to bleed the system when done..
Hi mate, you don't need to change the axle, the drums can be removed and replaced with the calipers/discs. It's pretty close to this conversion done on an EP70:
http://www.toyotagtturbo.com/forums/showthread.php?26125-How-To-rear-drums-to-discs
Hope that helps,
Jay