It's certainly doable, the complexity will depend on the version of the engine / car and therefore the electronic systems.
Your best bet for a car to put it into would be maybe a 1.8 because that would have the uprated brakes etc, but I gues you could swap a lot from the donor car anyway.
Personally I'd say get the car up on ramps and have a really good look underneath, a proper welding job from someone who knows what they're doing would maybe be a good solution and would save the car. Spend a filthy morning underneath it with a grinder or wire drill brush and get all the failed underseal etc from all around the sills / corners and wheelarches. Take the bumpers off and plastic trays etc. Do a proper job underneath and the body should see out the engine...