Insanely hard in regards to the amount of work required...that's what I meant Not as in difficulty compared to other conversions.
Converting to a 4A-GZE is a good start and that can then be converted into a 4A-GTE quite easily as well...I would look at that for a corolla - depending what corolla it is, of course!
3S-GTE is a bloody strong motor and makes good power so go for it if you have the cash!