I would prefer your solution #2. In your case I would make a normal Zip-File that includes whatever you want and call it s.th. like "Mr.PC ReaNote". In the description in the stash I would tell the user that it has to be unpacked and a changelog.
Another way could be to include the complete folder in the Zip, if there are more than one file included.
In your thread "Notation Sibelius Action List" you can then keep the link to the stash and don't need to correct it everytime you upload an update. Click my signature for an example if you want.
A little tip for this: copy the URL from the "HTML/Forum Codes" field in the stash to your clipboard (Right-click and "copy"). If you then edit your thread, you can choose "Insert Link" and paste it. Click ok and after that a part of the URL is marked in blue. This can be the text that is shown in the thread as a hyperlink.
If you right-click the "Download" button in the stash and copy
that as URL, the download starts immediately without making the detour to the stash.
Not what you exactly asked for, but...just to tell.