H1B transfering to a new employer

[Sam121]

Hi,

My name is Sam . I got my visa stamped in 2012 with validity upto September 2015 . I came to US by 2014 beginning and now planning to join another company by next month. I want to visit India in June for my marriage. In that case

1) Do I need to restamp my visa?
2) Is there any complication on Visa filing for my wife?

Please let me know your thoughts. I appreciate your time.

Thanks.
Sam.