Gravity Forms SMS user Validation using Twilio

I'd like to add in an SMS user validation component to a wordpress (3.9.1) gravity form. We have developer level Gravity Forms installed and forms built and working. I'm trying to validate that a user is Canadian using SMS, without having to be logged in. They just go to the form, fill it out, validate by SMS and submit! One idea is to use SMS validation instead of recaptcha prior to form submission (and anti-spam protection) (I'll use conditional logic: if they want to be validated by mobile, then recaptcha doesn't show, but SMS validation shows) I did come across this blog with some information that might be of use [login to view URL] Another solution may be in using WP SMS Verification plug-in, which also works with Twilio. There will need to be a method to validate if the area code is a Canadian area code (provided) If this works out, a secondly, if possible, would be a method to spoof VOIP/Twilio accounts and make sure that the number was a real number not a cheap or free VOIP. Please only respond if you are familiar with Wordpres, Gravity Forms and Twilio. Minimal hacks please that can break during upgrades etc.