What you can do is check out Belize'
for sale in the largest
for sale websites like
Multihull Maven, Yacht world and others. The specs indicate the
motor size and you can ask them of the prop size.
As I said, depending an your use of the
engine I would just buy two fixed blade 16" x 14" props. They quite
cheap and will do a reasonable job!
You have to bear in mind that these standard props are in no way optimal for any yacht, they are a compromise. To get your optimal prop the Maxprop is the only way to go since no folding props fits on the
Belize.
Good luck
Happy lead free sailin