Hello Joseph!

I set it to 1000 Mb, but it says "Maximum file size limit is 97.7 GB" 

As I may see in your UNA now, it transfers the values like 1024Mb to 1 Gb correctly. 97.7 GB - this is the size of your upload_max_filesize parameter so UNA can't allow the size with greater value then this one.

The same deal with the second part of your post - UNA can't allow more then you have in the server's settings.