If you want "high power" then you want a parallax adjustment, be it side or objective.

Not a fan of the Leupold 6-18x40.

The 4.5-14x40 doesn't really turn my crank either.

I like my VX-II 4-12x40AO, but it has a lot of eye relief even by my standards. If you use that scope, make sure the mounts you choose will allow you to get it forward far enough.

When you say Leupold mounts, which ones do you mean? There are many styles of those, some being less than ideal.