If you are doing an authentic neapolitan dough it will never see the fridge, so plan on doing at least two batches of dough a day. Many pizzerias in Naples do three batches daily. Typically it would be one for lunch one for early dinner, and one for late dinner/carry over to early lunch the next day (the dough will see the fridge for this batch but only till morning). Knowing this, you won't need a big mixer. I have used a number of different brands of spiral mixer, and they all seem to make the same quality dough (even the cheap chinese import ones). How long they will last, I don't know, but if it were me I would probably just get the cheap ones. Good luck!