Budget, goals? If you just want to get back to stock performance, you should be able to find a complete motor for your car for $800-900 in excellent condition. If you can't find a '96-98 motor, then a 2001-2011 2v 4.6L Romeo (01-04 Mustang or 01-11 Crown Vic/Marquis/TownCar) can be found with low mileage and nearly as cheap (cheaper if you look for a Vic motor).
2001 Ford Mustang GT Auto
2004 Chevy Colorado Crew Cab (daily driver)