that was a good bit of research Roberta
How are your woodworking skills msolga? Himself made a wooden post about 5ft/5ft 6in high with sticky out supports at the bottom (techinical term that

) to stop it falling in the wind and a simple wooden platform on top (the one the squirrels were sitting on) - we have an old metal bowl on it with water in and the birds love it.
Cheaper than buying a ready made birdbath as well.
Paddy-the-demon-cat did make it to the top once but by the time he scrambled up there any birds would be long gone.
Alternatively you could install the bird bath on top of a brick plinth, to make it much taller and harder for cats to jump silently.
my father took a water supply out to his and leaves it dripping very slightly, to constantly refill the bird bath

- - there's a healthy population of frogs amongst the flowers below it!