There are two general styles available. You can get a unitized unit that has everything, compressor, air handler, etc in one box. It is slightly bigger than a normal air handler with external connections for the water loop. You can also get a split to connect to a separate airhandler. It is smaller and has water and freon connections. ClimateMaster also makes a split unit that is designed to be mounted outside to replace an existing condenser unit. Be aware with a split unit, you should replace your existing airhandler to a newer unit properly sized and meeting the newer high SEER ratings. If you use an older airhandler, you may not get the expected efficiency.
In the attached picture you can see a unitized unit and a smaller compressor unit for a split, which are part of my installation.
paul