Petitioner Start Date & End Date for H4 Visa? based on H1B two i797. very urgent

[chatra]

Hi.

Here is the History :My passport has stamping from Company A valid until 2014 May.Transfered to Company B on april 2012 got i797 approval until march 2013 under Company B.As it is nearing for next extension, applied from company B H1B Extension and got i797 approved from April 2013 to march 2016.

So as above info I have two i797 one from april 2012 to march 2013 and another from 2013 april to 2016 march.

Question's

1) getting married in November and need to apply for H4 and what will be the Answers for below questions and do i need to having visa stamping done before H4 stamping for my Wife?

Petitioner Details

Start Date: Can i request for start date as any date after marriage date?

Receipt Number: Existing one or New One of I797?

Expiration date: until march 2016?

Thanks in Advance