This is more of a Way Heavy than a Wee Heavy!
Ingredients look fine. If you don't already have the base malt in your stock, give Golden Promise a try. How far were you going to boil the 1st gallon? Don't know if the whirlfloc is necessary or not in this beer.
156 on the mash is definitely on the upper end for a beer this big, IMO. Skotrat's Traquair House clone I brew is pegged at 154 and its OG is 1.088
Big starter . . check
62-65 on ferment temps . . check
I'd love to taste this one!