H4 transfer/extension when H1B change employer

USA H1B Visa
1

I have following queries:

I had my and my spouse visa and I94 expiring on Nov 2014 from company A. I switched my employer and as per my new petition my petition will be expiring on Sept 2016. I have not applied for my spouse H4 extension or transfer at that time. I want to do it now.

  1. Should I apply for the H4 transfer or extension now? If yes, which form I need to fill.

  2. If I file it myself how much charges are there for rejection. or I should take help from lawyer.

  3. My plan is once I got approval notice for my spouse H4 extension, we will go to India in Oct 2014 and get the visa stamped. so that in both our visa’s we will get Company B as new employer. Is this approach okay.