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The "best" QoS for a 7600 would require hardware that "best" supports QoS features; often found in WAN oriented line cards. FlexWANs support a rich QoS feature set, believe the SIP-200/400s do too.
Another "best" QoS approach for a 7600 is to not use the 7600, but perhaps front-end it with a more feature rich WAN router. Depending on how much bandwidth you're supporting for these tunnels, it may actually be more cost effective than some of the 7600 WAN type line cards.
Indeed some "extreme" QoS can be implemented with policing, but IMO it's like Civil War surgery, i.e. amputating a limb to save a life. So, recommend consideration of the above before going with policing solutions.