All I can really recommend is that you give
the guide a read (unabridged
here). Quality matters more than excessive quantity, and depending upon the Verizon LTE handset you might have and the region you live in, you're not limited to just CDMA service. I would also mention that if you genuinely do need Verizon service first and foremost, Republic isn't going to work out well for you, especially if you plan on using any mobile data. Nor will Ting. If phone service is that important to you, you need to pay for what actually works and you actually need.
As for trying to sell your unlimited data plan, what you're speaking of with Verizon is called an Assumption of Liability (AOL) transfer.
As of November 13, 2014, unlimited data plans are no longer valid for transfer and the new account holder must switch to a current data plan offering (
the vague verbiage in the official Verizon FAQ appears to confirm this). If you still want to try and do an AOL for whatever reason with your current handsets (if they're still under contract),
here's a guide on how to do it from before the Verizon unlimited data transfer moratorium. You'll note, it's a process that has a very slim window of opportunity if you want to keep your number. There's also services like
Cell Plan Depot that are designed to help sell contracts, though I have never used them or know anybody who has.
It's not rah rah happy news, but I hope this helps all the same. It is best to be sober and well informed of any significant financial decision, which is what mobile phone service is, even with a cheaper MVNO. Poor planing and research can still land you in a bad spot.