Hmmm!

Start Sigil
Type Title, Author ... Title page done
In Book Browser
Right click on "Text", Select new. Double-click on the New to open the page.
Click the add picture button, select file
Repeat until done
SaveAs...
Add a little more work to create the TOC:H tags (<h3 title="no visible heading alternate title here"</h3>) (view with F7), Metadata(F8).
Is that too complicated?