In the near future I am upgrading my pc which at the moment is running in a Antec Sonata II case. I am planning on modding the case and putting in a 120mm fan on the side.
The problem is that I need a fan filter/mesh to keep the dust out but I need to be able to get it cheap and not online.
Any help would be nice.
More aboutmesh case modding help
It would be better if you got rid of the old case and got a new one designed for use in 2012.
PSUs should be mounted on the bottom with the intake facing down. You won't be able to modify this into the Sonata case.
I am not sure how you intend for us to help you with the fan filter thing if you say you can't get it online and you don't tell us where you live.
Steal a fan grill from an old Pc, ask local shops if they sell grills, should be cheap enough if they do, or even forget the grill and just dremel out parallel lines on the panel to allow airflow through, always a way Moto