Your best bet is to call your cell provider and ask what works best on their network.

If not a google search for the things you have in your post along with "unlocked" should get you things to look at. It is very hard to recommend something since you have to know what bands you plan to use which data protocols etc etc. The reason you have to use unlocked is that you need a device that is not tied to a single carrier.

Still you planing to pay for a expensive month data plan from someone and as part of collecting that fee they owe you some assistance in device selection.