1g 2g head debate has not been proven as far as I have researched. Only true back to back I have seen was John Steel. He did a 6 bolt head swap with no other changes and lost spool/torque, he was dissappointed. This was on a 16g setup. And I wouldn't say AMS doesn't make an intake for a 2g. They do. They also make it for the evos. The EVO uses 2g size ports as well. The evos are making nothing short a rediculous power on the 2g size ports. There is an evo9 that Buschur just built that makes 650whp on his low reading dyno. That is about 900whp on a dynojet. It not only uses stock 2g port size it uses the STOCK evo intake manifold. I think its proven mitsu knew what they where doing when they made the ports the size they are today.

the setup you posted would be a ball to drive. the 3071 is a kickass street turbo.