If you must turn to urchins, go with Diadema setosum, though nearly any other Diadema will do. But that alone is no solution. Indeed, bubble outbreaks can be defeated WITHOUT resort to urchins:
The thrust of the article was that in a serious outbreak, you cannot get away from resorting to manual removal. Urchins and other herbivores are there mostly to take care of new, young sprouts.
Most bubble algae have to have 'bubbles' at least 1/3 to 2/3 their maximum size to be spore-bearing --so messy herbivorous action (mostly against new sprouts) doesn't release too many spores. The larger vesicles will have to be diligently removed (whole if possible). Some people use bare fingers to try to gouge, twist out the vesicles at the root, but I prefer an implement like a small (stainless) screwdriver.
On top of that, there is denying the algae their nutrients, and the article goes on at length describing how.
hth,
horge