formatting - Converting ms-word to ebook vs. writing from scratch?

Can anyone, who has any experience with writing ebooks, recommend a way for me to proceed?

I have a book in Microsoft Word heavy on mathematics: formulas (inline), equations (numbered) and diagrams.

I want to create an ebook from it (both epub and kindle versions), I was thinking one of two ways:

1. Convert Word document to ebook somehow



2. Write an ebook from scratch, striping all ms-word formatting

For #2 I am deciding between:

• LaTeX


• Markdown


• reStructuredText

PS: I use both Windows and Linux - so don't worry about OS, I can use anything (except MacOS).