we are looking to set up an extranet using Sharepoint foundation 2010. We currently have a WSS 3.0 server as our intranet (will be upgraded to foundation 2010 soon), this server pulls information from our SQL server (sql 2008 express), and then people connected to the network can see this information using either laptops, pcs or blackberry's.
We now need to put this information that the sharepoint server is publishing on to an extranet so that it can be accessed from any connection. I have attached a screenshot of a simple network diagram that i have designed for how i believe we would have to set it up. However money is an issue and we need to make this as cheap as possible.
In the picture i have 2 different domains, internal and DMZ, these will be 2 different forests with a trust relationship.
There are 2 different SQL servers, the internal one will be a copy of SQL 2008 std, working as a distributor and publisher, pushing the information we need displayed to a copy of sql 2008 express on the DMZ. The sharepoint server on the DMZ will be used to display the SQL information, and the sharepoint server on the internal server will continue to serve normally as the intranet.
We also need to collect information from the SQL server on the DMZ, and store it back on the SQL server in the internal domain which i am not sure how to do without risking security
So basically what i am looking for is
A - a way to accomplish what i am looking for.
B - Making sure that the internal domain is secure.
C - keeping costs down, we would prefer not to buy a copy of sql 2008 if it is not needed.
i appreciate any help on this and all suggestions will be looked at in detail.