AOS and H1B extention

Dear Members,

My H1B stamped visa valid upto Apr 2014. I-94 expires in May 2012.
1.Suppose in case if I file for AOS in next 3 months is it required to file H1B extention( to extend I-94 ) if I want continue in H1B until my AOS case is adjudicated and get GC in hand.
2. My spouse visa (H4) and I-94 is valid till Apr 2014. If I extend my H1B, should I extend spouse's H4 ?
[ Company /position/ duties/ location remain same ]

Note: We don't want to travel to Canada/ Mexico for I-94 extention. It is OK with my company to apply for H1B extention for I-94 extention.

Please share your ideas.Thanks for your time and attention.
-RGV1