Cable would be my choice for higher speeds. Also if you have cable TV, you might also add telephone and have a package price with your internet modem.
Here's a good place to start
I am not aware of any published "minimum internet speeds" needed. I have heard anecdotal evidence that an Internet Recovery may not function if your internet connection is slower than 1.0 Mbps, but you almost need to be in a public wifi hotspot to get speeds that slow anymore, at least in most urban areas...