懇請指導---L1B辦綠卡問題

I have been working for company A(Big US company but not in good financial condition recently) with L1B for 2 years.
Now comopany A agreed to extend my L1B and apply GC(Plan for EB2 not NIW) for me by L1B,and wage is above prevailing wage.
My questions are,
1.Is that difficult for L1B to apply GC? How long it takes if I apply EB2 not NIW?
2.I only have 3 years left for L1B, if company apply H1B(2008) for me next year,my GC application started with current L1B status need to redo again or can I use same PERM?
3. Company B got a 2007 H1B(effective from Oct.1) for me on 2006 April, but I do not want to move.Can company A use this H1B cap to do H1B transfer or apply 2007 H1B for me?