I rechecked Harpoons site and the IBU is 19. The hops I bought had a 3.8 alpha rather than the 4.8 listed so I upped the bittering to 1.25oz and left in the rest of the grain bill to get a net IBU of 18.2. Also the dry wheat malt was Muntons and was listed as 55% wheat and 45% 2 row. And as you noted it will be a little on the sweet side and that is what I was looking for.
Primary 1: Amarillo IPA
Bottled: Vertical Epic 090909 clone
90 schilling english
Hopmaster Imperial IPA