I'm really struggling to read what your asking here, as there is code not inside code markup in the middle of statements; making a somewhat unreadable mess I'm afraid.
You say you have a doubt about SSIS; what specifically do you think it is SSIS can't do here? I see you said something about that the definition of the file changes? If so, yes that'll be a problem. SSIS needs your files to be well defined. If the definition of your data keeps changing, SSIS won't be able to read it reliably; at least not with basic Source component.
If it's just the order of the columns (and the names are consistent), you'll likely need to use a Script Component to find the order of the columns and then appropriately read those values into the correct column in the buffer.
Thom~
Excuse my typos and sometimes awful grammar. My fingers work faster than my brain does.
Larnu.uk