So, I decided to fiddle a bit more with car design for the "long" trains. I'd note that the baggage car can go at either end.
Here's a set idea:
[01] Baggage Car
[02] Coach (59 seats)
[03] Coach (59 seats)
[04] Coach (59 seats)
[05] Coach (59 seats)
[06] Cafe/Lounge (N/A)
[07] Business (36-42 seats)
[08] Diner (N/A)
[09] Sleeper-Lounge (4 berths)
[10] Sleeper (28 berths)
[11] Sleeper (28 berths)
[12] Sleeper (28 berths)
[13] Sleeper (28 berths)
[14] Sleeper/Dorm (6-10 berths) or Bag-Dorm (0 berths)
Notes:
-Coaches are basically Amfleet IIs in terms of seat layouts, but should err towards Viewliners in terms of window space. A sticking point would be handling the upper windows (since closing blinds/drapes there could be tricky) and luggage rack space/placement.
-Business is a 2-1 configuration. Business pax have access to the diner (whether meals are paid vs included is a negotiable point). Inclusion of a bar/snack area is something I'd consider here (I presume there's a little bit of extra space to work with - my basis here is the Amfleet I Business-Cafe configurations, but potentially with a bit of extra seat pitch since some pax will be overnight-ish).
-The diner is a 42-44 seat diner (I presume the loss of a table due to ADA issues). On three meal turns this would give a capacity of 126-132.
-The Sleeper-Lounge essentially has 2-3 bedrooms on one end (I favor two slightly enlarged rooms), 4-6 tables towards the other (offering 32-72 extra diner seats), and some "social" seating areas in the middle. A bar is optional (but preferred if possible).
--> Four sleepers plus four extra berths equals 116 sleeper pax, possibly plus six if you do a sleeper-dorm and sell three bedrooms. So call it 120 sleper pax. A sellout in Business would add about another 40 pax with diner access rights, so 162-164. If the diner can fit 126, that needs another 34. I think the four table configuration is safe given that the odds of filling every sleeper berth (i.e. two per roomette) are pretty close to zero.
-The sleepers are all essentially Viewliner IIs in terms of capacity.
-The sleeper-dorm/bag-dorm car is a little bit of a wild card. I believe you'd probably need about 8-10 spaces in it for OBS (depending on the situation - I assume two coach attendants, 1 cafe attendant, 1 BC attendant (who depending on various decisions could augment the cafe or diner at certain peak times), 4-5 diner staff, plus one attendant for the sleeper-lounge (who would do food service for the "overflow" pax in the sleeper-lounge at mealtimes). So if you do sleeper space in it, you probably only have the three bedrooms (which could reasonably be attached to the neighboring sleeper).
Adding extra (non-coach) capacity from here gets tricky. If you wanted to add sleeper space, you'd probably need to convert the sleeper-lounge into another full lounge-ish car to add the requisite dining space, and indeed the kitchen might be a tricky proposition. One option might be something akin to a twin-unit diner (I forget how many tables those had, but if it mirrors the upstairs of a Superliner diner that'd give you 72 slots, and I don't think there's a reasonable design that lets you do much less than that "step"). And adding a bunch of extra cars starts to present platforming issues at a lot of smaller stations - a double-spot is one thing, but spotting 3-4 times is entirely another.