check the solidworks kb and the help for more information, but really the key file is the fld file.
any compression will work but you have to weigh the compression/uncompression vs the space savings. i find the compression isnt' worth it.
we put things on our ePDM server and usually put them in cold storage which goes onto a slow external HDD vs our fast main storage
and stay tuned to our website www.hawkware.com, we're working on a tool right now that will clean up any temporary files. right now you have to do that manually.
something to note, your setup will always be in the file (assuming you're using a modern version of flow)
so some customers will just accept that they need to rerun the sim and will only store the solidworks files.