The Berries: you can use frozen berries here but I suggest defrosting and warming (to avoid an iced latte).
The Milk: you can use any milk beverage you choose however, some of them froth better than others. You can refer to
this post for more information.
The Frother: my favorite is referenced in the post above.
Fiber! this latte is fiber rich which is groovy but go easy at first to acclimatize and ease possible gastric distress.