to ozonate water, yes those are great. but to ozonate olive oil i don't think i would use one of those. you need to continuously ozonate the oil for a considerable length of time, two weeks i believe. chances are the less expensive ozonators will burn out if you left it on for that long.
someone on this forum in fact complained about their ozonator buring out when they tried to use it for olive oil, but i dont know where that post it.
yes, that olive oil on ebay should be just fine for internal use, its just olive oil and oxygen, why would you be worried about it? in fact i think i will buy some come this payday so i can give you feedback then if you haven't tried it already.