Yes, those are the correct distances for those headers. It really depends on what you are trying to put under the Edison module but yes, I find it difficult to put anything in that little space. As for the connectors you can check this document https://communities.intel.com/servlet/JiveServlet/previewBody/23158-102-4-27348/edison-module_HG_331189-002.pdf . In section 3.8 are listed the product names for the connectors in different websites. I suggest you to keep checking regularly to see if they become available.