I have also been trying to get in one of the 787's or A321neo.. unfortunately, my schedule and the aircrafts schedule doesn't seem to line up ever..

Since there is no fixed schedule for these aircrafts, you need to check random sector everyday to see where they are flying.. the load these aircrafts max two day in advance.. in one case I saw the A321 loaded 6 days in advance.. the only common denominator was all flights originated and returned to Delhi..