Welcome to Toyota Nation!
There's quite a lot of info in the 6th Gen Corolla forum in regards to motor swaps. Feel free to have a browse around and make yourself at home

. Your plans for the Echo sound good. I've had the pleasure of driving a factory turbocharged Vitz RS in the past and it was a lot of fun. My Dad owns a gold 5-door
2001 Vitz RS (non-turbo though unfortunately). You'll find plenty of ideas and help for your girlfriend's ride in the 7th Gen Corolla forum too
Happy posting, and enjoy yourself here at TN!