Another suggestion is to put your system into a cabinet with an independant cooling/air flow system. Your room will always need air conditioning so I am not suggesting you do without, but if you were to build a cabinet for your system that has a vent coming if from below and then a vent at the top you can use a remote(attic) fan to move the air. This will avoid adding excess heat to the room during the summer and you can not use it during the winter when you want the extra heat.
All of the above suggestions using baffles,etc. can work but today's 'high efficiency' systems might not be able to force enough cooling air around all of your modifications to keep the air flowing at comfortable levels. One solution to this is to get a central blower that is well over-rated for the square footage of your house. Be very careful when restricting air flow: you might wind up outsmarting yourself and creating the a very quiet room....from hell.
All of the above suggestions using baffles,etc. can work but today's 'high efficiency' systems might not be able to force enough cooling air around all of your modifications to keep the air flowing at comfortable levels. One solution to this is to get a central blower that is well over-rated for the square footage of your house. Be very careful when restricting air flow: you might wind up outsmarting yourself and creating the a very quiet room....from hell.