We have about 25 employees in our current office and are looking to open up another office in another capital city housing about 15 employees. In our current office, we are running a domain hosted by a 2003 SBS server and I've been tasked by the boss to expand our infrastructure to the new office in the cheapest way possible (cheapest way in the short run that is, because my boss doesn't think more than 6 months ahead).

So I'm looking to get a second hand server and have it run Server 2003 Std with exchange server 2003. These are the things that it needs to do:

1. Replicate shared folders that are hosted in the parent LAN.
2. Deliver emails hosted in the parent Exchange Server
3. Somehow link up with the parent domain controller and push the AD to the remote site

I'm pretty sure 3 is impossible but the DC would be available if a VPN connection is present, right? On that note, would I be looking at hardware VPN connections?

I'm not sure how to deploy the new site as this is my first time doing it and i'm making it especially difficult for myself, seeing as the AD and DC is on an SBS server. Would I first start by establishing a VPN connection and then joining the new server to the domain? Will things 'just work' if I install exchange onto the new server and point outlooks to it? and how would I be able to replicate shared folders?