if i upgrade, i’m assuming i don’t lose any of our listings?
You shouldn’t lose any listing.
and do the URL’s stay consistent with the new version or will i have to do a mapping of old URL’s to new URL’s?
They should, you may need to go to Settings > Permalinnks and reset them.
I’d recommend making a backup of your database and wordpress directory before doing it (to be safe).
If you would like I can try to get a better insight without your sites current DB data if you’re able to zip up all of the WP and theme files being used on the site (minus the wp-config.php file, but all the others).