Suggestions for failover/data-rate limiting

[Sargon]

We currently have three BGP and MBGP peering sessions, one of which is 
an Internet2 peer. Our primary peering session (peer A) is a 100 Mbps 
connection. Our secondary connection (peer B) also is a 100 Mbps 
connection rate-limited to 19 Mbps (for financial reason). The 
Internet 2 connection (peer C) is a 100 Mbps connection.

Through various route maps, the Internet2 connection has the highest 
priority. Should that peer go away, Internet2 traffic will then route 
through peer B. All non-Internet2 traffic takes the path through peer 
A except for traffic destined for ASs within peer B's network.

I have been asked to find a solution which does the following.

A.  In the event of losing connectivity to peer A, bandwidth limit of 
19 Mbps to peer B is automatically increased to 45 Mbps within 1 
minute or less, and do this without any manual intervention (i.e., 
phone call to upstream to change the rate limit).

B.  The design will need to be resilient to failure (hardware 
redundant) or, in the case of failure, it should fail safely (do 
nothing but function as a dumb, pass-through device).

All suggestions will be greatly appreciated.

Thanks.

Sargon