You guys are failing the justification requirements stated at the top.
Who's heard of Aquitania? I mean, other than a few liner fans and a USS Shaw historian (Me). Better would be to see what the sales figured for Revell's 1/400 Queen Mary 2 kit were and go from there. I would see Queen Mary I as a viable option before Aquitania and as justification I would offer:
1) long history and well-known name
2) Still a living population of people who have sailed on her who have fond memories
3) She still exists and you have gift shop tie-ins (probably not a significant figure though)
4) Prewar, wartime, and post-war configurations so that you can sell multiple boxings and receive more profit from the initial investment.