I want to do constant width, if the prisms are 4.33" x 2.75" would I turn them sideways, which means I would only have the 2.75" to fit the width of my image into?

Do you mean constant height, for constat width you shouldn't need any prisms just buy a projector and go.

He wants a vertical compression lens. And technically yes that is what you would do.

Nate