Thunderroad

Good advice here. I wouldn't be too fixated on a 747, as some of the better first class options are on airlines that no longer fly them. Also, be aware that 100,000 miles will only get you one way in first class (and isn't enough for round trip in business class).

Off the top of my head, the best first class option using AA miles would be Etihad on its Airbus 380 from JFK, with its roomy, enclosed "apartments," followed by Cathay Pacific to/from a number of US cities, as its first class isn't enclosed but is very private. Service is generally great on both, though perhaps a bit more reliably so on Cathay. And if you want to take advantage of either airline's very nice first class lounge (since you'd only be flying F one way with 100,000 of so miles), you'd want the flight to originate in Abu Dhabi or Hong Kong rather than in the USA.

Both airlines would offer caviar, but not limos to the airport.

Qantas is another good possibility, but I believe snagging award F on it is even tougher than the other two, and perhaps to/from Australia might cost more AA miles.

British Airways might have decent availability and cost fewer miles than the others, but I'd still suggest steering clear of it. Not nearly as good as the other three and big co-payment charges for their award flights.

Hope this helps. Good luck!