to All Things Plants from me too!
I don't know much about cactus at all but those are lovely photos of your plants ... I especially love your database photos of that Golden Barrel Cactus!
If you are ever unsure of a plant's scientific name, don't hesitate to ask. We have some really knowledgeable and helpful members here on site ... they've been a tremendous help to me many times!
We have a Plant ID Forum: http://garden.org/forums/view/...
that is very helpful too and generally someone will recognize a plant very quickly and be able to give the name of the plant in question.
Again, Welcome to the site!