EZ Turnouts and Atlas Snap Relay

[LGBfan17]

I'm trying to do a layout based on an amusement park (https://adventureland.us/).

The layout of the real park: https://adventureland.us/adventureland-amusement-park-attractions-map/

I only need one turnout and it's a Bachmann #6 left (item 44859). Is it compatible with the Atlas snap relay as I want to have 2 trains? Each train with a B-Man 4-4-0 and 3x B-Man Jackson Sharp cars (one train yellow cars, the other brown cars that I already have). The engines are B-Man CP Jupiter and UP 119. I also want the train on the siding -- from the diverging turnout route -- to turn its engine headlight off when the points are set for the straight turnout route.

The instructions for the Atlas relay say to splice the lone siding feeder wire to the wire from the turnout frog and then put the whole connection to common on the relay, with both main line feeders going to the terminals on the other end of the relay. The power wires to the relay get spliced to those for the switch machine, which then go to the control box.

If it's significant, I will also have 3 other power blocks in the main track but these will all be spliced to a pair of bus wires, and all track power will be had through straight pieces with the hidden terminal plug. And the layout doesn't need a block signal because if one train is on the stub siding the other is operating by default as that's how the real park does it. My transformer is MRC Tech7 Ampac-700 which isn't even made anymore but the instruction sheet is still available. I believe the main bus goes to the DC terminals and the turnout controller, relay and switch machine all go to the AC connections -- all are Phillips screws on the power pack.

Additionally can anyone advise on a coupler with working knuckle for the Jackson Sharp cars? I'll be using a Micro Trains #1049 on both tenders, none needed on the engine pilots as double heading and combined trains will not be used.

[brokemoto]

Is there a reason that you must use the Atlas relay instead of the Bachpersonn?