I am no expert when it comes to stocking but what you are planning sounds reasonable. I don't really have any idea of what kind of bio load a frog introduces into a tank. Something you might want to consider is you probably won't have 5 guppies for long if they are mixed sex. After keeping guppies for just about a month we went from 8 to 18 guppies litterally over night.
Good choice on the gourami, I have always had great luck with the couple of gouramis I have kept.