ke55sdn

hey i just bought myself a ke55 4 door sedan, overrated condition only 58,000kms with original engine, its an wikid car but id like a bit more power and was thinking of putting a 3sge in it. id just like to know if anyone has done this before and could tel me how hard it is, and how much it would cost if i was doing most the work myself. also what drivetrain modifications would i have to do and could i use the original 5spd gearbox also will i need an engineers approval or anything like that