2.0 zetecs can be bought from £50 upwards - you can get a complete taxed and tested mondeo for a few hundred quid - then theres a bit of work to fit it - the 2.0s more powerful than the 1.7 more torquey - and only a tiny bit heavier, plus theres bags of tuning potential - fitting a 1.7 unless it was an FRP engine would be a waste and an FRP engine's gonna cost you a fortune