Replacing Existing Alarm System

Hello, We're considering replacing out existing alarm system when our annual contract runs out. We want to "cut the cord" and ditch our land line and cable TV and doing so would require us to replace our exisiting alarm system panel at a cost of $1000. Our questions: 1. Are we better off going with a Retrofit + 5pc Bundle Kit to utilize existing window and door sensors or building out a completely new Ring kit? 2. If the answer to #1 is the Retrofit option, does it require a land-line or internet connection for monitoring by Ring? Thanks!