L.M.
I actually just did this in october with well my six year old and 8 year old, so their a bit older. We went back to albany, red-eye, long.. long.. flight.. lol. I woke their butts up at the crack of five am.. and kept them buzy and awake all day, even though by about 8pm they were driving me insane (over tired)... they were excited for the take off and a bit after on the flight, then .. out like lights!
Good luck! Dont worry about the other passengers, I remember I had a guy request to be moved on a flight because he was sitting next to me and my 8 month old son, i could only laugh! Kids are just going to be kids!