Domain consolidation, and DHCP/DNS config with seperate subnets

so here deal.  we have 2 offices connected via vpn tunnel through 2 watchguard firewalls.  office has domain of "a.domain.com" , subnet of .1  office b has domain of "b.domain.com" , subnet of 0.  the domains have trust setup , things work fine.

we want consolidate b domain sake of simplicity.  

domain has has 2 dc's running server 2003.  one of supplies dhcp , both run wins , dns.

domain b has 2 dc's running server 2003 on one, , server 2008 r2 on other.  with 2008 r2 server handling dhcp, dns  and wins , other running dns , wins well.  

i have exchange 2010 running inside of domain b, linked mailboxes attached users in domain.

my question this.  lets wanted combine these domains b domain.  i want keep different subnets dont have reconfigure of printers , equipment has static setups, , dhcp server in each office each office handling own dns , replicating other office.  will work simple imagine working?  

the other question how move profiles in domain domain b , keep mailboxes in exchange attached them?

am wrong think if there wasnt dhcp server in either office machines try obtain dhcp through vpn tunnel other office?  that want avoid because obtaining address rely on internet connection working @ times.

i making change because plan on upgrading servers 2008 r2, , make change @ time.

here deal.  we have 2 offices connected via vpn tunnel through 2 watchguard firewalls.  office has domain of "a.domain.com" , subnet of .1  office b has domain of "b.domain.com" , subnet of 0.  the domains have trust setup , things work fine.

want consolidate b domain sake of simplicity.  

domain has has 2 dc's running server 2003.  one of supplies dhcp , both run wins , dns.

domain b has 2 dc's running server 2003 on one, , server 2008 r2 on other.  with 2008 r2 server handling dhcp, dns  and wins , other running dns , wins well.  

have exchange 2010 running inside of domain b, linked mailboxes attached users in domain.

question this.  lets wanted combine these domains b domain.  i want keep different subnets dont have reconfigure of printers , equipment has static setups, , dhcp server in each office each office handling own dns , replicating other office.  will work simple imagine working?  

other question how move profiles in domain domain b , keep mailboxes in exchange attached them?

wrong think if there wasnt dhcp server in either office machines try obtain dhcp through vpn tunnel other office?  that want avoid because obtaining address rely on internet connection working @ times.

making change because plan on upgrading servers 2008 r2, , make change @ time.

Windows Server  >  Migration