Note that a lot of PG texts have formatting such as *bold* and _underline_, etc.
If you briefly turn the text to HTML first, replace such tags with simple <b> and <u>, etc. tags then import to OpenOffice, you will also get nice formatting in addition to your normal font choices.
I believe that there are several Gutenberg to HTML scripts and utilities to do it for you. (GutenMark?)
Then you will have your chosen font, layouts and possibly TOC, etc.
PG also offers HTML, too, for many works.