I know the 99 hardtop won’t fit, the windshield is at a different angle and they have different mounting points between the two models. As far as engine and tranny, I suppose anything could be made to work but it won’t be a bolt in swap. Newer year motors have more sensors and may not talk to your ecu. Plus depending on what transmission the donor 99 has, it can change your driveshaft lengths. Also depending on what motor and tranny you have now VS the donor, the transmissions/transfer cases have different input and output spline counts.
as for parts that would switch over, I think mainly you’re looking at seats, tires, maybe some other small things for a direct swap. All else will need modification