Question : Problem: Is there a good solution for this scenario?

My customer currently sits in an office that he shares with his secretary.  He has an XP pro laptop.  She has Win 2k system.  They both connect to the Internet via an old Linksys BEFSR41 (not V3, and firmware could be upgraded to 1.46.02).  Their DSL account is dynamic.  They both have private static addresses in the 192.168.1.xxx range. He runs ACT!, but the ACT! files are on her system.  She has access to his Briefcase.  He can print to her shared printers.  Everything works well.  However, he has decided he wants to work from home, using his laptop, (150 miles away), while she will remain in her current location.  He would prefer not to lose any of the current functionality.  He will have a broadband connection from home, probably also dynamic, with no router.  
Question:  What is the best solution?

Answer : Problem: Is there a good solution for this scenario?

Best solution (not the only solution):

Obtain public static IP addresses at one or both ISP.  Then, get two identical routers that can terminate a site-to-site IPSec VPN tunnel and install them at each site.  Configure them to reach each other via a 3DES or AES IPSec VPN tunnel.  This way, the manager can virtually be at his old LAN while being at home and still have access to everything.  Ensure the private IP address range of the new site (his home) does not overlap with the other LAN.