Bandwidth bonding with SpeedFusion is a site-to-site VPN technology available on the Balance 210 and higher routers.
We do have a virtual appliance that you could deploy at a datacenter or on the AWS cloud called FusionHub, more details here:
Another option you could look at is that we have a partner that offers the bonding as a service which means they handle the other side of the SpeedFusion tunnel using our products. It is called Simply Bonding: http://simplybonding.com/
Thanks!