Pitch a big starter and use a blow-off. I had a 5 gallon batch blow off nearly 1 gallon and it was in a 6.5 gal. bucket. Also, don't be too discouraged by the gravity samples if you taste them as far as that "rocket fuel" flavor. It goes away in 6 to 8 months.
The recipe looks similar to the one I bought from LHBS, should be okay. I don't know why the two crystals, they will add something similar in the ratio of the grain bill. If you were to change or add something, I might add some peated malt for a little earthy flavor, 1 lb maybe.