Restrictive Covenant in Employee Agreement

I have an employment agreement signed with my employer to not join any of the clients of the company for a period of 18 months. My client has offered me a position to join their organization and wanted to know if I can safely consider it or will there be major implications. I have been with my current organization for 2 years now and there were promises made of stock options, green card processing, etc all of them verbal. I have not had my performance review done, no appraisal, no promotion, no stock option, no GC processing in the last 2 years. The employment agreement states that "employee submits to the jurisdiction and venue of the appropriate courts of Begen County, New Jersey in any proceeding arising out of, or relating to this AGREEMENT". My current organization is based in Houston, Texas.