It's not SoFplus related. You could always use a .bsp file. Just put the map in user-server/maps/dm/iraq_final.bsp and it will work.
A .pak file is just a way of grouping multiple files into a single file. When your map requires additional files, like custom textures, it's easier to install a single .pak file then to install a lot of files in multiple locations (user-server/maps/dm/somefile.bsp, textures in user-server/textures/.../somefile.m32, ...)