Yamaha 90 2004 prop suggestion

[Justpete]

I have a 2 stroke 90 on a recently purchased Zodiac Pro 9. The prop that cam with it is steel not aluminum and not stainless by the look of it... Or poor quality stainless.
It gets up and goes very nicely and reaches WOT very easily. I want to buy a back up ppaluminum prop and wanted some sizing advice.

Does anyone have a similar set up with something that they find works well?

I typically have two adults and 3 young teenagers in it, a cooler and a I have a 24 gallon gas tank under the seat.

Thanks!!
Pete