Migrate 2008 r2 to 2008

HI, i am from Spain, excuse my English

I have a 2008 r2 domain with 2008 native level and 1000 users, 1000 PC Clients and 60 Servers (SQL, Files, Printers, App)

I need migrate all users, groups, Clients and Server to 2008 domain and i have some questions:

1) What is the better versión of ADMT for those OS versions? 3.0, 3.1 or 3.2?

2) What is the better migration secuence?:

     first PC clients

     second Users

     Third Servers

3) Is necessary create a two-way trust between source and target domains or isenough one-way trust?

4) When i finish migration will have my Clients the same profile with their documents?

5) Are there some moment where clients don't have Access to resources (files and share folders in servers)?

6) Can i preserve production and no interruption in PC Clients in the migration process?

Thanks for all