Hello Jeremy, I was kind of confused at first too regarding all the options, but I think I got it all down.
There is two options. Phone tethering, which is slow, but works for radar updates. Second is an aircard, usually USB, or express card.
Depends on what kind of stuff your gonna be doing while chasing
1. Are you gonna be streaming video to a website? If so, you will definitely need the aircard, as you will be using more bandwidth. For streaming, I would also HIGHLY recommend some sort of external antenna.
2. If you are just gonna need the internet for radar updates, phone tethering will work just fine.
As far as service goes, the main two candidates are Sprint and Verizon. Sprint has the best hands down, but the only downside is that you have to sign a 2 year contract with your aircard, and the $60/month can add up. Verizon on the other hand has good service, but not as good as sprint (very small difference). I ended going with Verizon, because you can just buy an aircard on ebay or somewhere for ~$70, then activate it, and use it month to month, so since i wont be using it in the winter, I can shut it off, and not have to pay the $60/month
You'll need cash too of course
Ill let you look into that, and if you have more questions, I or someone else would be glad to respond.