^^^^Agreed on both the sensitivity and H30. I have a 2X12 vertical slant cab w/ a V30 and a G12H30. They compliment each other well.If you want to mix and match speakers (a great way to tweak tone by the way) It's best to stay with the same or very similar efficiency ratings.
Since your V30's are 100db try to stay around 100db.
Best match with V30's I've ever heard are H30's to be honest...