You can change the pulley on the compressor as the compressors on their own are the same, but you will still need brackets to mount it inline with the crank pulley.

You COULD change your 4age to use the 4ac pulley setup, you will just need to get your alternator pulley converted to a V belt and whether it will line up is a question itself (you can remove the crank and water pump pulley and fit it to your 4age). That way all your a/c stuff will bolt up.