There is no such thing as unlimited mobile data. A few companies advertise but if you read the fine print they throttle it back or add extra costs if you go over a certain amount it data. And it's not very much.
You need to ask yourself how much data you plan on consuming. Do you stream movies and download a lot of entertainment or are you a casual user that checks email, social media and weather and occasional on line banking.
If you stream you will need to pay for a lot of data. Probably in the 20-25GB range if not more.
If casual use then I am certain you can get away with a plan of 5GB or less.
VZ hotspot/Jetpack is probably the best coverage and device available.
If you already have a smart phone, check to see if it can be used as a hotspot. Will use more data sop perhaps your plan may need to be adjusted but it may save you from buying an additional piece of hardware like a jetpack.