Hi
you need to do policy routing here where you based on the matches you define on the routers either the source address from where the traffic is getting originated or the remote address to which the traffic is destined.
You can define the same using normal Access - Lists which will help to define the required parameters.
Or even you can match both the source and destination address and route it accordingly.
Once you have the ACL then you can think of defining the route-map under which you can define primary next hop and secondary hop by which you can achieve redundancy for your critical server traffic.
On the other side for the default traffic just have a default route for other traffic and a floating static route towards secondary 2M link.
http://www.cisco.com/en/US/products/ps6350/products_configuration_guide_chapter09186a008042fbeb.html
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter09186a008075fae6.html
regds