best prop recommendation for the following setup

[dreamland s4]

i need a prop recommendation for the following:

proboat hydro 1:8

5692 leopard 1000kv

8s 5000mah 40c lipos

swordfish 240amp HV

i was told a 450 would do but just in case can anybody point me to some safe props to start with?

thanks people! cant wait to get her going nicely!

(i dont expect super speed, but at least 50mph would be nice)