As with everyone here, I too suggest it would be wiser to use your dad's expiring AA miles to book both of your trips. Not only does it extend the life of your dad's miles, it is the most efficient way of using award mileage rather than transferring miles between rival companies.
Just checked using the
webflyer mileage converter, the best it comes up with is 200,000 AA miles =
25,500 US Dividend Miles via HHonors
On a side-note, domestic AA Awards allows one stop over within the lower 48 states. So you could do something like PHX-MCO-LGA-xxx-PHX and head off to Disney World on the way ^
My advice:
Book a trip to New York with a stopover at MCO using your dad's AA miles = airfare covered ^
At the same time, transfer some of your dad's AA miles to HiltonHonors and use that for staying at Hilton Walt Disney World Resort ^
Have fun at Disney World
