My brothers and I attempted it last summer and we really loved the way it came out. Not sure we cloned it 100%, but it was close and really good. I will post the recipe we used later tonight when I'm home.
1 pound of DME is equal to approximately 1.67 lbs of grain. So 2lbs of wheat extract would be the equivalent of approximately 3.34 lbs of grain. However, since wheat extract is a mix of malted barley and malted wheat, you'll need to split those 3.34 lbs between the two grains. Maybe 50/50? So, maybe ~1.67lbs each of 2-row (or pilsner perhaps) and wheat malt.