Your loco should look very good with the pictured 8 wheel passenger cars which come in many colors. I'd stick with the tab and slot unless you really want to "automatically" couple. It's relatively easy to pop existing couplers off the passenger cars once you remove the roofs. You can even install Lionel box couplers if you like. When I swapped some stuff and ended up with the American Flyer cars I also got the PRR type tender but no locomotive. The previous owner had obviously swapped the tender T coupler with a Lionel latch. In addition one of the coaches had a latch at one end and tab and slot at the other. I restored the coach to two tab and slots and run them behind an AF 1218 electric. If I ever find the correct loco I'll change the latch coupler on the tender to tab and slot.
Lew
