LibreOffice or Apache Open Office?

I'm liking LibreOffice. I've had Open Office for years too. I think you'd be fine with either.

Currently the differences between them are mostly about the user interface. I'd try one, and if it's not quite to your liking, then try the other.

It's is mostly a matter of which version of which; some are better than others. As was suggested, trying one and then the other would be a good idea. You might even want to download both and try them the same day and o the same things.

Open Office is at high risk of being cancelled

Since LibreOffice is Open Office, except with a slicker front-end, my advice would be to go with LibreOffice. LibreOffice has a healthy development cycle as is likely to be around for many years - particularly if Apache cancels Open Office and the devs there are free to go over to LibreOffice.