FIRST OFF, i'm not a lawyer... i'm just waiting for a response to my own question, and came across yours.Thought I might be able to give you a bit of insight b/c my husband is also unlawful, although, he does have a VALID work permit(EAD).. using a fake work permit is a serious offense... They may decline your application just on that alone.
The two options we had were: #1)take our chances and apply for AOS or #2)leave without applying and start over somewhere else. Bottom line, if we apply and get approved, WONDERFUL! If we apply and get denied, it would mean a MUCH MUCH MUCH harder life, probably in a country where we didn't know the language... and is without clean water.. but it would not be the end of the world. God has a plan for everyone. If you make a decision and go forward with it FULL heartedly, the end result may not be exactly to what you initally WANTED, but it will be as it should be.
Good luck!

Thought I might be able to give you a bit of insight b/c my husband is also unlawful, although, he does have a VALID work permit(EAD).. using a fake work permit is a serious offense... They may decline your application just on that alone. 