Can SMS 2003 work in a multi-domain environment via VPN?

I am trying to determine if SMS 2003 can work in a multi-domain environment connected only by VPN. My current needs are: remote control of clients, package deployment based on OS version, and if possible logging of services and some asset tracking. My main questions regarding this setup are:

Would SMS work if I setup secondary services in each domain? Would I be able to remote control a user's machine from one domain to another?
Using SMS over VPN can be done, but it is not terribly straightforward. However, author Dana Daugherty has written several articles on dealing with the challenges of SMS over VPN, which can be found here: http://www.myitforum.com/contrib/default.asp?cid=171&p=9. (If your problem is that the (remote) computer object in the collection is set to the address of the internal network and cannot be remotely managed via that address, the best way to resolve that is to add the IP address of the client to the SMS server HOSTS file.)