apply for a job once you get the sponsorship and your file been filed i think you dont have to maintain your F1 status ( iam not sure about this check with lawyer) are you in california?? if you are then its easy to find sponsorship. Now a days lawyer aske for the visa screen certificate before they file a petition.coz you get your GC bet 5 to 6 mons ( depends on where you live) let me know if i can be any help