I'd go for the AE1-P, for three reasons (of which two seem valid and one less
) :
1) it'll be more recent than the "plain" AE1
2) it has no needle for the display, which is one breakable component less (I like the LEDs of the AE1P, and they are easier to use in low light than the needle)
3) the AE1P was (and still is, still works fine 28 years later) my first "real" camera.
The AE1P is not very advanced but it has interchangeable focusing screens (without the need to send it to a camera tech person) and the display is quite nice (the brightness adapts to the light level, and the LEDs are behing the numbers, so that even in low light you can read the number perfectly)).
I also have a preference for the handling of the AE1P, if it has the small grip on the right face.