To make it less confusing I updated Cant find Hard Limiter Effect - #2 by Gale_Andrews . Please read that topic. The latest alpha development builds noted there (and 2.0.4 release later this Autumn) will contain a new built-in reverb effect to replace GVerb (that is, GVerb will not be included in 2.0.4 release and may be removed from the development builds at any time).
So if you want GVerb, it is probably best to make sure you have the current Audacity 2.0.3 release from Audacity ® | Download for Mac OS . Read the installation instructions for Audacity on that page.
When you have 2.0.3, download gaclrecords.org.uk, extract GVerb and any other files you want from that zip, put them in the Plugins folder in /Applications/Audacity then restart Audacity.
Gale