I mounted my intercooler in front of the condenser.
You want a little space between all the components in the cooling system to help minimize radiative heat transfer. Sometimes you just run out of room though. In my installation I have about 1.75" of clearance at the bottom of the IC to the condenser, but at the top it's down to about 1/4" because I had to tip the intercooler back for hood latch clearance. The condenser is about 1/2" away from the radiator.
It's also a good idea to have some of the condenser exposed to clean air if possible.
Since you mentioned pusher fans... keep in mind that puller fans are more efficient that pusher fans.
Another thing to keep in mind is that idle and low speeds the heat load on the intercooler is minimal so it won't be shedding a lot of heat to decrease the efficiency of the condenser; however it will still restrict some of the airflow. When intercooler heat loads are high (i.e. under boost) you're usually already moving along at a good clip and will have plenty of airflow.
Here's some pics of how I did things...
http://home.comcast.net/~procharged69/intercooler.htm