Aircon retrofit

[DoctorBonzo]

Hi there, i'e posted this on the chim forum as well but wonder if anyone here has experiencing of retrofitting aircon to their car? I'm moving to Australia and want to take my '97 chim with me. I thought Aircon would be useful as even roof down motoring can get incredibly hot in summer. Does anyone have any idea of how difficult it is? How much to budget? Is it worth it?
Thanks