Well as you alluded to, your total air wing will determine the floor area of your hangar. As for actual deck height - it's not like with a normal deck that pretty much has a set height that's practical for a person to be in. That's going to be determined not only by the size of your aircraft, but the size needed to crawl around them as well. Fun fact: US WWII carriers had decks tall enough to actually hang aircraft from the ceiling: