Has a load calculation been performed for this home? With the possible inclusion of the products you've described above...was the six ton figure arrived at with those materials in mind? Offhand six tons seems a bit much for 3,500 square feet, but I can't see the house plan or architecture from here.
How about your window choices? Have you considered radiant barrier roof decking vs. the other product mentioned above? Easier to apply...the radiant barrier is already part of the deck. Once the rafters are sheathed with decking, the radiant barrier is in place and goes to work immediately.
If the length of the house runs north/south (broadest wall areas of the house facing east and west), I could see some benefit from the low E house wrap if both facades will receive considerable solar exposure in summer. If either facade is deeply shaded, maybe not. Hard to give east and west facades enough shade from dawn to mid-morning, and from mid-afternoon to sunset without very broad overhangs, patio covers, trellises, shade trees, etc.
The caveat for any of these products you are considering to work at maximum benefit is correct installation techniques applied. Same goes for your HVAC system and ductwork. You can have the highest end, most highly lauded energy saving technologies in place, but if they were not selected and installed with care, full benefit will be diminished.