Thanks for input everyone!
I spoke to 8X8. Dynamic is OK, and 100kbs is enough.
I am just have trouble understanding there pricing scheme.
Since my practice is starting up, currently all I need is ONE phone number, and ideally 2 phone devices, (although one phone is adequate for now). However, they require a subscription for each device. I thought VOIP was supposed to be a affordable solution as I was used to an old-school AVAYA system that allowed multiple extensions while paying for one phone line.