There are several Stoppas in Venezuela. I live in Valencia, Venezuela, and a friend of my brother was married to a girl named Simona Stoppa, of Italian descent. They are now divorced, and live in the US. You can look up her name in Facebook and maybe send her a message to see if she replies..hopefully she is interested in trying to find out a thing or two about her roots, too, like all of us in these forums. Or maybe you have found new information since your posts and have reconnected with your family members.
Also...Santa Cruz does not sound like a city in venezuela unless it is a small town...could it be Puerto La Cruz instead..? A lot of Italian descendants there...it is on the Eastern Coast in Venezuela.