Questions regarding claim tax return with parents as dependents:

I have a few questions regarding claiming tax return with my parents as dependents:

1. Can I file my parents' w-7 first, then file my 1040 after I get their Tax IDs?
Or should I file my 1040 with parents' w7 (and notirized passports).
Which way is better?

2. I'm a US greencard holder, so on W-7, I should choose "dependent of US citizen/resident alien", right?

3. where do I input the info. that they have stayed here >183 days?

Thanks!