Id ditch the td06-18g and go with a blouch xtr series turbo. Also bigger injectors and and an e85 safe fuel pump so you have the option of tuning on e85 as i assume you are going to run 98 predominantly? You may also want to look at getting a decent aftermarket
ecu, link offer some really good plug in ecus and there are plenty of shops around who can tune it.
Drivetrain wise you will also need to look at upgrading to a 6spd gearbox 100% at thpse power levels. Not sure how the r160 rear diff would go at 400 so you may even need to go the whole hog and do a rear r180 conversion.