I am wondering if it would be possible to have one router at each site and connect them to two modems each and establish IPSEC tunnel interfaces through each of the modems to the other site and do equal cost per-packet load balancing i.e. the "no ip route cache" command through the tunnel interfaces to get higher bandwidth between the two sites.
LAN---[Cisco Router]---Modem1A=======Tunnel0=========Modem1B---[Cisco Router]---LAN \\---Modem2A=======Tunnel1=========Modem2B---/
TIA