Whoa there smart guy [Victor].
To answer your OP, yes those fish will work in a pond.
I would do a half dozen Pacus, up the GT number to 15, make the Gourami an even 20, and add a few more JD's. Wouldn't have to give smart-A answers if the questions were not there...If you are in a location where you are concerned with winter temps. just do the goldfish. Getting a pond built and cycled in two weeks isn't going to happen. Using guppies as canaries is a waste of time. You're going to keep 600 gals., probabaly above ground, heated to 77+ deg. for guppies. Seems like a lot of effort.