The two best I know of atm are beluga and anaconda. I have two with the same number of cabins. Albeit the beluga has some 3's and the anaconda has some 4's. Beluga also has luxury(for if I find a base with lots of luxury missions) and the beluga has First class. Anaconda has 60+ly while the beluga is barely 50ly jump range. Basically the differences for my ships.
Anaconda Passenger ship
Beluga Passenger ship
I prefer the anaconda for general missions as it has the cabin sizes for getting more/better missions and the jump range is just the right distance to one jump a lot of locations reducing jumps for personal convenience. It is called the ill repute for a reason though. It's easy to die in. Beluga is literally just for if I can manage to find a place with mass luxury missions to farm money. Anaconda is basically for reputation grinding with the missions to visit x+X tourist beacons.
Not sure how much the 4 first class vs 3 business class matter. I don't use the beluga a lot because of jump range atm. the beluga in that setup has much faster engines though. It may be better for getting in and out fast for illegals.
Not sure how to find mass luxury missions yet either. Hoping to find that out one day to use that beluga.
And yes, if using sheildless prepare to die potentially. It's par for the course. But it's also funny and can add RP value as you kill alot of passengers in a really kitted out vehicle! 8)