As you know< I changed from 5 speed automatic to 5 speed manual shift.
Transforming an USA Outlander is a bit different than a JDM Airtrek.
Firstly, the engine is different. To make life simple I would do a Evo 8 engine swap. That's just me.
The head swap could be your alternative though, but i don't know much about that.
For the Airtrek, the complete evo 8 front suspension can be swapped, except the anti-sway bar and end links, and uncludes arms, axles, hub spindle, knuckle, abs sensor, etc.
I used coilovers suited for the Outlander, check the web on Ksport.
I use the body bars from Ultra Racing.
It is for the chassis number beginning with CU2W.
Hope this helps.