Plastic Selection

I'm going to have an online machine shop build a part for me using a CAD drawing that I specify.

Typically, these parts are made of Aluminum, but this manufacturer also mills parts out of these plastic materials:

• Polypropylene (PP)
• Polystyrene (PS)
• High impact polystyrene (HIPS)
• Acrylonitrile butadiene styrene (ABS)
• Polyethylene terephthalate (PET)
• Polyester (PES)
• Polyamides (PA) (Nylons)
• Poly(vinyl chloride) (PVC)
• Polyurethanes (PU)
• Polycarbonate (PC)
• Polyethylene (PE)

Polypropylene, I know, is the plastic used in Water Bottles, so I know that is not what I want.

This fabricated part will be used for the Clutch Cover on a motorcycle transmission and will have a raised section that needs to be tapped to allow attaching a gear shifter to, like in the Aluminum version below.

I'd like something rigid and strong. Plexiglass comes to mind, but there could be a better alternative that I am unaware of, as long as I am not getting into something exotic that would cost more than Aluminum.

Is there a Chemical guy on here who could suggest a good plastic for me?

Naturally, the material would need to be oil resistant and withstand typical engine transmission temperatures.