I've just ordered some Burris Signature Zee Rings with Pos-Align Offset Inserts, these allow you to change the POI without having to make large adjustments on the turrets, just small ones to fine tune!
There is also an insert with gives you 20 MOA change at 100 Meters! so it sounds like they could be right up your street.
There's a little video explaining how they work on the link below:
Burris Signature Zee Rings
Another plus point is they don't damage/mark your scope!
Hope this helps
J
Id be interested in how these perform. Post when you get them set up and lets