Personally, I wouldn't hesitate to do the Corsa/Volant exhaust, Volant CAI and ECM upgrade. Each of these upgrades is small by themselves, but the total of them together should get you close to what an 07 has. We have the 07 and it is just right (any less and I would be unhappy).
Not sure if there's a header available for the H3, but if there were and I had an 06 - I would do that too.
Keep in mind that driving that many miles in any vehicle will have you wanting to sell. I get sick of driving after that many miles
