there are 3 liners - a prison liner, a luxory liner and the bretonian royal liner. i guess you know them allready. for the bretonian royal liner, i think you may want to have a bit of RP about why to get it - it is supposed to be slightly rarer than the very common spa and cruise luxory liners.
when its about NPCs - they mostly travel in armoured transports anyway.
AoM has presented a slaver liner in the ship submission thread which would add to the liner fleet. - but no other liner is currently being designed or planned, i think. when it comes to roleplay - they should most probably be more limited to what they are designed for
* passengers or VIPs on the luxory liner
* prisoners or living cargo with high security ( maybe nomad samples ) and slaves in the prison liner
* passengers or VIPs on the royal liner
Don't know if the Slave liner will be finished til next version. I hope it can be done til then. Doom was working on a Rheinland liner. Don't know about its progression. Doom?
We have also the Beetle, named as Kusari Cruise Liner.