The Super Shute 90 requires a hole size of 117mm x 59mm.
The Elvstrom/Andersen requires a hole size of 110mm x 54mm.
Choose the one that is closest to your existing aperture size.
The bailers are not subject to wear and tear in normal use so either material will be suitable.
I have not used the plastic type for comparison but I suspect the SS may be more robust if subjected to rough treatment.