Change from H1 to F2 visa

[Michael]

I am on H1 visa which is till september 2014. My company has started my green card processing and now its in the recruiting stage. Once they submit the application it takes 4 to 8 months to know whether I'll get a green card ie. it might be February 2015 till I get an answer. So I might have to exit US before I know anything about my green card. My question is:

1. Is there any way to stay in the US legally till I get an answer about my green card processing?

2. If I change to F2 visa(my wife becoming F1 visa) ,will it affect my green card processing?