How soon can I apply for I-485 after getting approval for I-140?

[barbismom]

Hi,

We recently got our I-140 approval and wanted to know how soon we can apply for I-485.

Is there a need for the priority date to get current for us to apply for I-485? Or can we apply for it right away?

Also, is it possible to apply for EAD and AOS separately (than I-485 application- if this has to wait for priority date to get current)?

What are the restrictions for job change under these circumstances?

Thanks in advance.

barismom