Domain controller, what do I need?

Archived from groups: microsoft.public.win2000.active_directory (More info?)

Merging from Netware to Microsoft 2003 Server. I need some help making
decisions on my network structure. New network to be as follows:

General:
-Five total offices (4 branches and 1 Corporate) to use centralized SQL
database.
-Wan connections via DSL-VPN from branches to Corp office.
-Terminal server(s) to be used to run sessions of SQL based software package.
-About 30-35 total users company wide
-SQL Database size about 1.5 to 3 GB.
-Exchange server to be added in future to centralize e-mail, share company
calendars etc.

My data will now be critical. Target Restore is about 4 hours.
Availability now becomes very important.

I need to determine my server needs and configuration (how many of each).

Domain Controller(s): Based on my scenario, # users, do I need to have more
that one DC?

I have read that I should not mix my Domain Controller with ANY other
services (DNS, DHCP) or software like SQL etc. However, my number of users
is very small (30-35), so is it ok to have one DC with DNS and DHCP roles
setup on it? Can Is it ok to run any other software on a DC?

I have also read that in the event of DC hardware failure that requires a
new server, that it is nearly impossible to RESTORE the DC (and active
directory) on different hardware. Is this true?

If I have only one DC, then basically a DC backup (system state) is useless
in this case and I would have to start from scratch, re-add my users,
re-create profiles, re-create policies, groups and all the like. My backup
would only server to restore user files and data.

For availability, I understand that 2 DC’s would keep things running in the
event of hardware failure in one, but in a fire etc, I would lose BOTH of
them anyway. So do I go with 2 DC’s and just pray that I never lose both of
them in fire or catastrophe?

I need to make the best decision on my number of DC’s. Is it better to
spend the money and get the second DC or can I RESTORE a failed DC from
backup with little difficulty?

I know you can ADD a new DC to an existing domain from a restored backup of
an existing DC to new hardware. If you can do this, then how can restoring a
single DC to new hardware be so difficult as I have read?

Will a DC based on my users (30-35) run ok on a 733 MHz, 256 MB RAM, single
IDE HD box?

Thanks much,

Mark