The one issue that could potentially frustrate you is that you need to be sure you return the Voipo ATA, no matter how long you've had the service. As always, I recommend that you use a carrier with tracking.

Other than that, porting back should be straightforward--just call the Verizon business office, and ask them to set up a new line, and indicate that you want to port your number in. You can always see if they're offering any win-back promos... (Chances are, you won't get any if you don't ask, so nothing ventured nothing gained.)