Errr.. Paradise fish are quite, quite aggressive fish. They are nothing to mess with, and have not a problem with shortly becomming the tank bully. If you want your betta to stay in one piece, I would not place him in with a Paradise fish.
Betta's and gourmis in general are really not good combinations. I've tried. I put a betta in with my Sunset Thicklip gourmi. The gourmi was in the tank already and had been living there three months before I bought the betta home. Well, the betta did nothing but no stop harass the poor gourmi unitl I took the gourmi out of the tank. So I figured, okay, try again, and just yesterday bought a small Blue Gourmi to put in the tank. Same thing, the betta just continued to chase the poor baby around and around and harass it constantly. This harassment is not a good thing for fish because the fish that is constantly under attack from a bully will usually get stressed out, sick and, well, croak. The Sunset and Blue are now very happily getting along in my other tank, and mr. bully betta is busy flying around after some white clouds.
So personally, if I were you, I wouldn't try a betta gourmi combo. The closer the fish look or behave like each other, the more likely they are to fight, even between species, because the set of competitive signals for dominace are almost identical.
~~Colesea