steve, the loaf grande is very different than the fresh grande. the fresh grande would give you a neapolitanesque, or an elite NY style taste. The grande loaf would be a good version of standard pizza cheese. If it were me I would buy the fresh because I like the style and taste, but I think you could get away with keeping the loaf in your fridge for a much longer amount of time without needing to freeze. I am not a huge fan of pre frozen cheese, but my guess is that the loaf would probably hold up better than the fresh once thawed..
Having said all that my absolute favorite cheese is Buffalo Mozzarella from the area around Naples Italy. I am not sure if the brands you mentioned are from that area or not, but the pre frozen buffala might not be such a bad choice if you have to buy in bulk. I would think they have a "process" for freezing that makes it hold up better than freezing cheese yourself would.