Congrat on your new purchase. I do have the same car (2000 4.4l sport package) with 81k miles. This car still drives and looks like brand new. I had several issues between 55k and 65k (Radiator, Water pump, Final stage resistor, Window regulator, Control arm, etc...all fixed under the extended warranty) but since that not one single problem.
As LeMansX5 said at that mileage a lot of the known issues of this model should have surfaced by now. However, if you have the possibility to buy a good extended warranty I would strongly suggest to do so. It also pays off to do some of the work by yourself if you have some manual skills. For a lot of things you do not need to be an expert mechanic. For example a brake job done by yourself can save you a lot of money and this Web site will be there to help you. Enjoy the ride.