20ft containers only come in standard height IIRC, I have the exact dims of the doorway if needed.
You should be able to drive in but the exiting from the vehicle will be difficult as the 100s are wide and will have a problem getting out of the drivers door once inside, I would plan to go for a exit out of the rear tailgate.
I would consider isolating the battery and leave it unlocked at least you can access the truck to push it out of the container if you have any problems when unpacking it.
You will need several good ratchet straps to secure the truck whilst in the container so have them to hand it is a pain and quite awkward as there is not much room to move around inside the container once the truck is inside but there are plenty of tie down points to use,
Lastly make sure you are shipping as hazardous goods so you can leave the fuel and battery with the truck if not you will need to drain the fuel and remove the batteries, there is a price difference so work out what the penatly is for a HAZ or NON HAZ.