My question is how did you get recruited. Do you know someone there, send a resume in, answer a job posting, how did they know to approach you. If they came out of the blue and approached you for a corporate gig, I'd be very leary, it works the other way around. Most stable corporate jobs are mired in secrecy and have companies that search and conduct background checks and also do most of the interviews. Think about this; are they going to hire you, someone they don't even know much about and type rate you and let you fly the boss around. Would you do that if you were hiring someone. I know I wouldn't. And I am not attacking your professionalism or skills as a pilot, I am trying to share with you what a good flight department would do for a pilot's position. One of the most difficult decisions a department manager can make is hiring the right pilot. That's why so many referrals are usually involved, it takes some of the pressure off and helps you look into someone you've never met. If you've never met the person and don't have anyone at the company that knows him, the only thing you have at first is a resume. if that's all they have , be careful. The process should start with a resume, then continue to background checks, tests, and at minimum 2 interviews, and employment checks and letters from current and past people you've flown with. It takes a while to sift through all this if done correctly, especially tracking down referrences. Do ya see where Im going with this. If this or a good portion of what's stated here isn't happenning, approach with caution. If this is his first jet and it's a Gulfstream then that brings up a red flag to me already. It can be done but it's very uncommon. Most people have started out smaller and grown into one after a couple years. Seeing that they've been around for a year alleviates some of that but still proceed with caution.
You'll never gain the necessary PIC time you'll need to get into the legacy carriers as fast as in the regionals
Good Luck!