I would love the Boeing XB-17 (Model 299), the prototype B-17 Flying Fortress (in addition to the B-17 of cource). I think it’s even more beautiful than the B-17 and would be a really cool transport plane in Neofly, Airhauler, etc. Check it out:
The Messerschmitt 323, “The Gigant”, both four and six engine version, is another special plane that would be cool in the sim. Looking forward to the Lancaster later this year:):)