What is a good ECU for a 2002 Subaru Forester to lower peak torque to around 2000rpm and what other effects could the unit have on the vehicle?

What is a good ECU for a 2002 Subaru Forester to lower peak torque to around 2000rpm and what other effects could the unit have on the vehicle?
You could put it in N out of D an the rpms will lower.