I've wanted to do this for ages because I hadn't seen it anywhere so I used PHP/HTML/CSS & GD code to take 3 JPEGS then combine them in all possible combinations so I wouldn't have to do them manually in photoshop.
It's not very good/balanced data but I can tell the code to load any registered images to combine so will try with some others soon.
And I don't think I've seen an index like this anywhere else? (Is there one?)
I think it's a nice little preview tool that could be used to view all possible combinations before doing a proper processing job in photoshop or whatever. At the very least this index might give you some ideas
UPDATED: Have a live version of the tool running online here if you want to feed it your source Ha/Sii/Oiii Jpegs and watch it process your own images: http://deography.com/tmp/test/
d