Visiting Zipolite and Mexico City

I am hoping to visit Zipolite in February and looking for some tips on where to stay that will be peaceful, affordable and close to the beach. I am more spiritual than a party animal so hoping it still has its hippy vibe.

I also might spend a night or two in Mexico City to avoid my flight from London, UK being too long (having to wait 7 hours for the connecting flight). Would you say it is worth seeing? Anywhere to go nude there?