Well since your using a flat network you could try this [URL=‘http://fogproject.org/forum/threads/requested-multi-site-location-patch-requested.410/’]multi site patch[/URL]. Lee is the man on this but the downside is you have to .031 for it to work as there are changes to the coding on .032 that keep this from working. So long story short you create locations and tie them to FOG servers with each computer then add the secondary FOG servers to the main FOG server as part of the default storage group and use DHCP to control which FOG server the computers boot from and the location make the computer pull from that machine.
Then you can setup the replication to happen in off hours or throttle it so that the link between the two sites isn’t overloaded. Look this over and hit me up or ask Lee since he made the patch and hes really nice and walked me through getting it hammered out.