A used late model oem windshield works great. From the few aftermarket windshields I seen on the mk3 Supra some do not have the black trim around the glass (so you do not see the dash/interior side pillars edges and/or the sealer used). Also the top tint could be a miss also with the aftermarket windshields so if you go aftermarket I would inspect it for these items.
I'm on my 3rd windshield, but the car is on the 4th. The last one I got at a local glass shop, I guess around 2003. It has the tint along the top edge. And, whadaya know? Mine has a thin black border around the top and sides with dots to fade away. Glad I got all the trimmings!
As I recall, there are 2 colors of glass available, one greenish and one brownish. That's something else to consider.