There's always the Jeep SRT8 in the x5'ish size realm, or a Cayenne GTS.
I don't begrudge the power requirement, but in this era of the 2.0 turbo you are probably going to have to have some wiggle room.
Our x3 with what? 300HP, can get a little "sluggish" when it's loaded down, but it's still faster than 98% of the other stuff on the road. You shouldn't really be racing around with 2 kids in the car anyway.