You DO NOT want the exhaust fan over the door.
Put fan in rear then on hot days you can open the door and the fan will pull through from the front.
I have never seen a commercial Gh or for that matter a hobby GH with the exhaust fan over the door.

It's a little hard to give advice as you don't mention the greenhouse dimensions or what the power demands are for the types of equipment you'll be running (fans, heating, seed propagation mats, radio, misters, thermostats, lights, etc.) In general, outlets on both sides of the greenhouse are important, as is the use of weatherproof box covers (like "CodeKeeper" brand) to protect outlets from water spray, and it's essential to have ground fault protection.

I have 1 HAF fan with thermostat and speed control, two motorized shutters and one exhaust fan with one thermostat and speed control. Plus one heat mat, to root plumerias, solar light. There are 2 circuits coming in. I saw a picture someone had of a wood board with the thermostats and controllers mounted on it. I can't seem to find it now when needed. I have the HFGH 10 by 12. The thermostats and controllers to the exhaust fan are going to be hard wired.

You may be talking about mine.
I have my GH wired with 80amp service and it is none too much. Depends on how many lights and how you are going to heat it.
I heat with electric heaters

Here is a link that might be useful: {{gwi:298299}}

Yes, that's the one. Thanks for posting it.

That is just a 1/4" piece of plywood and I used U bolts to clamp it to the steel tubes on the end of the shelves

Here in HOT Arizona we make the back wall a huge cooler pad and draw it through to the front of the house, in effect making the gh a huge swamp cooler The fan is in front as we need as much pad area as possible at 115 degrees and the fan takes up less area.