Selection Chart/Menu

Firstly apologies if this is the wrong section for this request, wasn’t sure where to put it.
Some time ago I created the following simple selective menu system:

http://www.galebreakeragri.com/siteenglish/prodselector_uk.html

using the (now obsolete) MenuMachine on the (now obsolete) Adobe Golive.
It still works on some browsers but not iOS browsers, amongst others.
I’m going to be rebuilding the site from scratch using WordPress and was wondering how to replace this chart with one that works on this platform.

Any advice much appreciated.