Iphone and Mifi Data service for Suzhou and Shanghai.

Will be these two cities for August and September 2016. I have a Huawei mifi device that I would like to get a data sim for, and also an unlocked iphone that I would like a voice and data sim for.
My questions are:
--Is 4G LTE offered in either city?
--Which carrier is best for each of these devices? Used to be China Unicom worked best with Iphone, but that has probably changed by now.
--Is there a website in English that I can view plan pricing for any of the carriers?