I was wondering about the kingsguard at Aerys' death, I know that Jaime Lannister, Oswell Whent, Gerald Hightower, Arthur Dayne and Barristan Selmy were in the kingsguard, who where the other two? Was one Prince Lewyn of Dorne?

Yes.

The other was Ser Jonothor Darry, brother to Ser Willem.