Winter is citrus season in south Texas. I've made this citrus salsa with combinations of pummelo, grapefruit, oranges, clementines, tangerines, blood oranges, cara cara oranges. I would save lime for the juice portion of the recipe. The sweeter varieties work better in this recipe.
See this article for help removing citrus pith.
It is difficult to provide a number or weight for the oysters. We had medium-sized oysters, and allowed 2 per taco. One would be sufficient if the oysters are large, and 3 if they're really tiny. The tub may indicate number and size on the package. One-half pound drained should be sufficient for 2 people.
A deep fryer will provide the best results, but I don't usually want to use that much oil and then have to clean my counter top appliance afterward. I have found that about 1/2" oil in a heavy fry pan (ie. cast iron) works well. Use good tongs to turn the oysters, and be very careful to not get the oil so hot that the breading burns. Conversely, oil that is not hot enough will result in greasy oysters!
I will not pretend to give you macro nutrients on this dish. There are too many variables! My apologies!