In the uk there pretty much dealer only and some models are no longer available. A few of us have imported them from the states for quite a decent saving see the link below http://www.imoc.co.uk/forums/viewtopic. ... sc&start=0
The cheapest option is to buy from a Denso supplier in the US, Denso make the condensers (and driers) for Toyota so they are exactly the same.
If you are changing the condenser you will also need to change the AC receiver/drier, these should be renewed every 2 years or whenever the system is opened/regassed.
If you go here and do a car model search it will tell you the part numbers you need, then do a Google search for the part number to find a supplier. I recently did this on mine and the saving over OEM Toyota prices was huge. http://densoautoparts.com/find-my-part/ ... -selection