Maybe you should try to upgrade to 64bit flavour as a clean upgrade. Still, you could do the upgrade on a single machine. XAMPP is available in https://askubuntu.com/questions/921315/how-to-install-xampp-on-my-ubuntu-16-04-32bit
Do not take anything marked x64
All the best with the install. Our infrastructure runs on Ubuntu 18.04 (LTS) server edition. We do not lose over head in running a graphics interface.