help Design Active Dir. for company with 4 offices

Hi all,

I couldn't spot any other place to post this so pardon if this is the wrong section. This thread is to discuss opinions about a solution i need to design for the client...

If there are any MS Server / Exchange Admins onboard on TE, I seek your opinion & consultation.

I Need help designing Active Directory for a client who has 4 branch offices and one head office. The 4 sites have user email IDs in Same primary domain as well as 2-3 more domains, which are sister concern companies for the Primary company.

Biggest question : Should I use SBS or use 2008 R2? or regular 2008 R2

If I close down to single forest/domain, I want ideas on how to create my FIRST server. what I plan is:

Primary domain: company.com

Other regd. company domains: companyLABS.com, companyTECH.com

4 sites have people working for all 3 domains stated above. So I plan to make 4 sites:

site1.company.com
site2.company.com
site3.company.com
site4.company.com

All above 4 sites will be part of one major AD: company.local (company.com). This AD server will be at a 5th location where the IT manager will have physical access to this Primary AD server, she'd be controlling all policies from this which will be in affect on other 4 sites...

Please shed some more light on the plan...

Also I do plan to use Exchange for emails.. but later... once all data is centrally managed, practised and adapted by the underlying users at all 4 sites. There are a total of 5 email domains that will be required....

The client currently is not using any collaboration tools like sharepoint etc. They don't even have client server architecture at the moment.. all computers at different sites operate in a hay-way workgroup mode. No centralization at all.. That is the concern for the stakeholders, as the company has grown more than 5 folds in past 5 years, they are a pharma company who is into
1. Manufacturing medicine -Labs and Pharma plant (primary domain)
2. Research in Bio technology
3. IT arm of this company making ERPs for pharma companies. They develop & sell customised Software to many small and medium pharma companies (small team of 15 people)

As stated, I'm to start from scratch for them, so instead of rushing to put up a server there, I want to dedicate time in planning...

At the moment, we need to start with first H.O. with around 25-30 people. I need to put a first server there, configure "AD for this site only", configure folder redir for users and if possible create exchange for them too!! Then give this a test run for a month or so. This AD can be remotely managed by the IT Manager and "me"

Likewise once the stake holder's are satisfied, we move to second site, do the same, put a server there, centralise data adn move to third and 4th site

Once all 4 sites have 4 Servers (4 ADs) setup and running separately, the IT manager, who heads the ERP development team and sits at the 5th Site, will get a NEW Server, which will be configured to be as the SUPER AD. all 4 previous servers will connect to this one server for AD backup (data backup will be treated seprately per site) and will impose policies to underlying 4 servers as set on the SUPER AD.

my explaination above my not adhere to how AD actually works, but thats how the flow of action needs to be with the client. SO I seek some pointers on how to design EACH SERVER individually for each site, so that later when all 4 sites have servers, we can create trusts between them, or join all of them to a SUPER AD to get their policies etc..

I hope I was more clear on the scenario, thanks for reading up...
My main dilemma is should I put 4 SBS servers at each site or should I make them as regular ADs in a single forest. cost is concern to the company.. so help me decide

Regards...