Fresh Green Card, Should I apply in Premium

[kulhrishi]

Hi,
I have just submitted my docs[ I140 and I485] to my employer for my EB1 C which are under review.

Now
My Visa expires on 25 Nov 2011, I94 Expires in April 2014
My Wife's visa expires on 25 Nov 2011, I94 Expires in August 2012
My Daughters's visa expires on 25 Nov 2011, I94 Expires in December 2012.

We don't plan to leave the country for next 3 months so I have'nt submitted the I131.

Is it safe enough to get all the approvals and the GC till August 2012 OR should I ask my employer to file for Premium Processing...

Please help...

Thanks and Regards
kulhrishi