Actually 10:1 with aluminum heads for pump gas is a good solid recommendation. Look at Autoxcuda's combo and you'll see that his engine will ping on pump gas at 9.7 compression. Lots of variables to play with but 10:1 is a very reasonable number.
If you want some proof then go look at the specs for production high performance cars. Most of the high performance cars made these days are in the 10:1 range and they are morre sophistacated than anything we build. They have knock sensors, computer controlled ignition timing, computer controlled fuel injection, etc. If you don't have the automatic compensation systems then you have to dial the base engine design back a bit.