Most of us use either the 6-12016 Lionel FasTrack terminal track or make our own FasTrack terminal tracks.
When needing to connect to or from a Molex power connector (say on the PH180), we either cut it off or make our own adapter using the requisite components:
Molex Female housing 538-03-09-2032
Molex Male housing 538-03-09-1032
Molex Male pins 538-02-09-2103
Molex Female pins 538-02-09-1104
You may also see use of Banana Plugs with various equipment, like on a CW-80.
Edit: One last option which I forgot to mention is that you can cut the cord off your cost reduced and less capable LC power supply and connect it to your more capable transformer and continue to use the barrel connector on the FasTrack or make your own barrel connector wire with a standard 2.5mm x 5.5mm male connector.
