Difference between OEM install and custom Ubuntu image

The OEM Install

• The OEM install allows machine by machine customization.
• It does not create an ISO image, but customizes a single machine.
• Customization is done at the stage of installation.

Advantages

1. Do not require a custom iso.
2. Each machines can have different customization.
3. Suitable for small number of customized machines, each with its own set of customization.
4. Also suitable for uncustomized machines where user gets to setup her own settings.

Disadvantages

1. If each machine needs to be customized the same way, they still have to be done individually at the time of install and thus, will take longer.
2. You will need some other tools to create an iso image.

Custom Ubuntu Image

• On the other hand custom Ubuntu Image allows making a single customized iso.

• Copy it in multiple CD/DVD/USB

• Deploy the same image in multiple machines quickly.

Advantages

1. Suitable for large volume deployment of identically customized machines.

Disadvantage

1. Requires an extra step of creating and testing a custom iso image. May not be worthwhile for one or two machines.

An OEM version is for manufactures of computers (system 76 for example) whereas the custom Ubuntu image is made so you "personalize" an image. If I was you, I would just do custom image.