i know a bunch or people that got dynoflash on there evo's. they do it according to your mods. you can either mail the ecu or make an appointment with them. they are in nj i believe. yeah its a whole new car and its an easy reliable way to make some good hp.
http://www.dynoflash.com
check out the site. they will probably be able to give more feedback. They know what they are doing and they do evo's on a weekly basis