I assume one of your books is "Pennsylvania Railroad: Passenger Trains, Consists and Cars - 1952 / Vol. 1: East-West Trains" by Harry Stegmaier, Jr. It's very handy for this task.
As for the trains themselves, I'm working on completing prototypical consists for some through trains, using the KATO BL sets as basic building blocks and reworking several manufacturers' stock cars to make the prototypes I need: PB70, 8-1-2, 14 section, P70Gr, P70FBR, 6 DBR-Lounge, and others. I also kitbashed a prewar boattail obs but then Bachmann came out with the exact prototype (of course). I did use the old RR/Atlas PRR observation to make the almost similar version of the Harbor that was used on trains other than the BL. KATO did sell 21 roomettes in a separate add-on set, so look for those on the net. Other non-KATO cars you can use are the MTL parlor, the IM P85s, and head-end stuff like x-29 express boxcars (several mfgs) and limited-run kits for B60b and R50b, tho I think those are not available anymore.
MicroScale has a pretty good selection of car names on their PRR decal sheets -- one is nothing but names - which also allows for some cut and paste to get specific names. There are no 14-section car names but I managed to piece together enough word parts to get one. Their PRR decals are pretty decent, you might want to look at them before you have some custom made.
I hope someday to sell these PRR consists --- since I've since changed to the NH. Except I have to finish all the conversions first.