I have the dreaded upper intake manifold leak and am planning to purchase a new aftermarket manifold before the problem gets worse. Does anyone have an opinion whether an aftermarket manifold (like the one at the 1A Auto site) would be even better off if reinforced with the Pure Performance manifold repair kit or would this just be overkill. (I hadn't planned to do it this way, but was curious).

Not necessary. The manifold solves the problem, and is the best solution.